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L. Valore

Publications and source records attributed to L. Valore.

13 recordsLinked to original sources

Enhancing Water Cherenkov Detector Arrays through multiPMT Modules

Water Cherenkov Detectors (WCDs) are pivotal in various scientific fields, including neutrino physics, gamma-ray astronomy, and cosmic-ray research. The detection sensitivity and precision of these detectors crucially rely on photomultiplier tubes (PMTs) to capture Cherenkov radiation produced by charged particles moving faster than the speed of light in water. In recent years, employing multiPMT modules has emerged as a promising strategy to enhance large volume water and ice Cherenkov detector performance. In this work we explore the use of a multiPMT module in small WCD units, arranged in arrays as typically used to detect Extensive Air Showers (EAS). We outline a possible configuration and present the advantages it can offer for data analysis, as demonstrated through dedicated simulations. We investigate the potential of multiPMTs in capturing the features of the Cherenkov light distribution originated by single muons and discuss its possible application for muon tagging in WCD arrays.

astro-ph.IM

The Fluorescence Telescope on board EUSO-SPB2 for the detection of Ultra High Energy Cosmic Rays

The Fluorescence Telescope is one of the two telescopes on board the Extreme Universe Space Observatory on a Super Pressure Balloon II (EUSO-SPB2). EUSO-SPB2 is an ultra-long-duration balloon mission that aims at the detection of Ultra High Energy Cosmic Rays (UHECR) via the fluorescence technique (using a Fluorescence Telescope) and of Ultra High Energy (UHE) neutrinos via Cherenkov emission (using a Cherenkov Telescope). The mission is planned to fly in 2023 and is a precursor of the Probe of Extreme Multi-Messenger Astrophysics (POEMMA). The Fluorescence Telescope is a second generation instrument preceded by the telescopes flown on the EUSO-Balloon and EUSO-SPB1 missions. It features Schmidt optics and has a 1-meter diameter aperture. The focal surface of the telescope is equipped with a 6912-pixel Multi Anode Photo Multipliers (MAPMT) camera covering a 37.4 x 11.4 degree Field of Regard. Such a big Field of Regard, together with a flight target duration of up to 100 days, would allow, for the first time from suborbital altitudes, detection of UHECR fluorescence tracks. This contribution will provide an overview of the instrument including the current status of the telescope development.

astro-ph.IM

INFN Camera demonstrator for the Cherenkov Telescope Array

The Cherenkov Telescope Array is a world-wide project for a new generation of ground-based Cherenkov telescopes of the Imaging class with the aim of exploring the highest energy region of the electromagnetic spectrum. With two planned arrays, one for each hemisphere, it will guarantee a good sky coverage in the energy range from a few tens of GeV to hundreds of TeV, with improved angular resolution and a sensitivity in the TeV energy region better by one order of magnitude than the currently operating arrays. In order to cover this wide energy range, three different telescope types are envisaged, with different mirror sizes and focal plane features. In particular, for the highest energies a possible design is a dual-mirror Schwarzschild-Couder optical scheme, with a compact focal plane. A silicon photomultiplier (SiPM) based camera is being proposed as a solution to match the dimensions of the pixel (angular size of ~ 0.17 degrees). INFN is developing a camera demonstrator made by 9 Photo Sensor Modules (PSMs, 64 pixels each, with total coverage 1/4 of the focal plane) equipped with FBK (Fondazione Bruno Kessler, Italy) Near UltraViolet High Fill factor SiPMs and Front-End Electronics (FEE) based on a Target 7 ASIC, a 16 channels fast sampler (up to 2GS/s) with deep buffer, self-trigger and on-demand digitization capabilities specifically developed for this purpose. The pixel dimensions of $6\times6$ mm$^2$ lead to a very compact design with challenging problems of thermal dissipation. A modular structure, made by copper frames hosting one PSM and the corresponding FEE, has been conceived, with a water cooling system to keep the required working temperature. The actual design, the adopted technical solutions and the achieved results for this demonstrator are presented and discussed.

astro-ph.IM

AtmoHEAD 2013 workshop / Atmospheric Monitoring for High-Energy Astroparticle Detectors

A 3-day international workshop on atmospheric monitoring and calibration for high-energy astroparticle detectors, with a view towards next-generation facilities. The atmosphere is an integral component of many high-energy astroparticle detectors. Imaging atmospheric Cherenkov telescopes and cosmic-ray extensive air shower detectors are the two instruments driving the rapidly evolving fields of very-high- and ultra-high-energy astrophysics. In these instruments, the atmosphere is used as a giant calorimeter where cosmic rays and gamma rays deposit their energy and initiate EASs; it is also the medium through which the resulting Cherenkov light propagates. Uncertainties in real-time atmospheric conditions and in the fixed atmospheric models typically dominate all other systematic errors. With the improved sensitivity of upgraded IACTs such as H.E.S.S.-II and MAGIC-II and future facilities like the Cherenkov Telescope Array (CTA) and JEM-EUSO, statistical uncertainties are expected to be significantly reduced, leaving the atmosphere as the limiting factor in the determination of astroparticle spectra. Varying weather conditions necessitate the development of suitable atmospheric monitoring to be integrated in the overall instrument calibration, including Monte Carlo simulations. With expertise distributed across multiple collaborations and scientific domains, an interdisciplinary workshop is being convened to advance progress on this critical and timely topic.

astro-ph.IM

ARCADE - Atmospheric Research for Climate and Astroparticle DEtection

The characterization of the optical properties of the atmosphere in the near UV, in particular the tropospheric aerosol stratification, clouds optical depth and spatial distribution are common in the field of atmospheric physics, due to aerosol effect on climate, and also in cosmic rays physics, for a correct reconstruction of energy and longitudinal development of showers. The goal of the ARCADE project is the comparison of the aerosol attenuation measurements obtained with the typical techniques used in cosmic ray experiments (side-scattering measurement, elastic LIDAR and Raman LIDAR) in order to assess the systematic errors affecting each method providing simultaneous observations of the same air mass with different techniques. For this purpose we projected a LIDAR that is now under construction: it will use a 355 nm Nd:YAG laser and will collect the elastic and the N2 Raman back-scattered light. For the side-scattering measurement we will use the Atmospheric Monitoring Telescope, a facility owned by the Colorado School of Mines and placed in Lamar (Colorado), the site where our experiment will take place.

astro-ph.IM

Applications of muon signal to electromagnetic signal showers universality for mass composition and hadronic interactions studies

We present the first results of the application of the recently found universality of behavior of muon signal to electromagnetic (EM) signal ratio with respect to the vertical depth of showers maximum for mass composition and hadronic interaction studies. Making use of the fact that for zenith angles above 45 degrees the dependence of the ratio on the vertical depth of shower maximum is very similar for QGSJET II and EPOS 1.99 we show that this provides the possibility to estimate muon shower content in almost interaction model independent way. To evaluate the excess of signal in the data in respect to Monte-Carlo predictions we propose to use mass independence of the electromagnetic signal. Using the simulations with EPOS 1.99 as a fake data we show that one can determine the absolute scaling factor between these fake data and the interaction model under test (QGSJET II in our case). Applying this scaling factor to the total and muon signals of QGSJET II one can make accurate conclusions on the primary mass of samples prepared with EPOS 1.99.

astro-ph.HE

Precise determination of muon and EM shower contents from shower universality property

We present two new aspects of Extensive Air Shower (EAS) development universality allowing to make accurate estimation of muon and electromagnetic (EM) shower contents in two independent ways. In the first case, to get muon (or EM) signal in water Cherenkov detectors it is enough to know the vertical depth of shower maximum and the total signal. In the second case, the EM signal can be calculated from the primary particle energy and the zenith angle. In both cases the parameterizations of muon and EM signals are almost independent on primary particle nature, energy and zenith angle.

astro-ph.HE

Precise determination of muon and electromagnetic shower contents from shower universality property

We consider two new aspects of Extensive Air Shower development universality allowing to make accurate estimation of muon and electromagnetic (EM) shower contents in two independent ways. In the first case, to get muon (or EM) signal in water Cherenkov tanks or in scintillator detectors it is enough to know the vertical depth of shower maximum and the total signal in the ground detector. In the second case, the EM signal can be calculated from the primary particle energy and the zenith angle. In both cases the parametrizations of muon and EM signals are almost independent on primary particle nature, energy and zenith angle. Implications of the considered properties for mass composition and hadronic interaction studies are briefly discussed. The present study is performed on 28000 of proton, oxygen and iron showers, generated with CORSIKA 6.735 for $E^{-1}$ spectrum in the energy range log(E/eV)=18.5-20.0 and uniformly distributed in cos^2(theta) in zenith angle interval theta=0-65 degrees for QGSJET II/Fluka interaction models.

hep-ph

Precise determination of muon shower content from shower universality property

It is shown, that highly accurate estimation of muon shower content can be performed on the basis of knowledge of only vertical depth of shower maximum and total signal in ground detector. The estimate is almost independent on primary energy and particle type and on zenith angle. The study is performed for 21500 showers, generated with CORSIKA~6.204 from spectrum $E^{-1}$ in the energy range $\log10(E)$ [eV]=18.5--20 and uniformly in $\cos^2θ$ in zenith angle interval $θ=0^\circ-65^\circ$ for QGSJET II/Fluka interaction models.

astro-ph.HE

New approach to primary mass composition analysis with simultaneous use of ground and fluorescence detectors data

We study the possibility to reconstruct primary mass composition with the use of combinations of basic shower characteristics, measured in hybrid experiments, such as depth of shower maximum from fluorescence side and signal in water Cherenkov tanks or in plastic scintillators from the ground side. To optimize discrimination performance of shower observables combinations we apply Fisher's discriminant analysis and give statistical estimates of separation of the obtained distributions on Fisher variables for proton and iron primaries. At the final stage we apply Multiparametric Topological Analysis to these distributions to extract composition from prepared mixtures with known fractions of showers from different primary particles. It is shown, that due to high sensitivity of water tanks to muons, combination of signal in them with $\xmax$ looks especially promising for mass composition analysis, provided the energy is determined from longitudinal shower profile.

astro-ph.HE

Measurement of Aerosols at the Pierre Auger Observatory

The air fluorescence detectors (FDs) of the Pierre Auger Observatory are vital for the determination of the air shower energy scale. To compensate for variations in atmospheric conditions that affect the energy measurement, the Observatory operates an array of monitoring instruments to record hourly atmospheric conditions across the detector site, an area exceeding 3,000 square km. This paper presents results from four instruments used to characterize the aerosol component of the atmosphere: the Central Laser Facility (CLF), which provides the FDs with calibrated laser shots; the scanning backscatter lidars, which operate at three FD sites; the Aerosol Phase Function monitors (APFs), which measure the aerosol scattering cross section at two FD locations; and the Horizontal Attenuation Monitor (HAM), which measures the wavelength dependence of aerosol attenuation.

astro-ph

The Lidar System of the Pierre Auger Observatory

The Pierre Auger Observatory in Malargue, Argentina, is designed to study the origin of ultrahigh energy cosmic rays with energies above 10^18 eV. The energy calibration of the detector is based on a system of four air fluorescence detectors. To obtain reliable calorimetric information from the fluorescence stations, the atmospheric conditions at the experiment's site need to be monitored continuously during operation. One of the components of the observatory's atmospheric monitoring system is a set of four elastic backscatter lidar stations, one station at each of the fluorescence detector sites. This paper describes the design, current status, standard operation procedure, and performance of the lidar system of the Pierre Auger Observatory.

astro-ph

The Central Laser Facility at the Pierre Auger Observatory

The Central Laser Facility is located near the middle of the Pierre Auger Observatory in Argentina. It features a UV laser and optics that direct a beam of calibrated pulsed light into the sky. Light scattered from this beam produces tracks in the Auger optical detectors which normally record nitrogen fluorescence tracks from cosmic ray air showers. The Central Laser Facility provides a "test beam" to investigate properties of the atmosphere and the fluorescence detectors. The laser can send light via optical fiber simultaneously to the nearest surface detector tank for hybrid timing analyses. We describe the facility and show some examples of its many uses.

astro-ph