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R. Battiston

Publications and source records attributed to R. Battiston.

At least 19 recordsLinked to original sources
arXiv2025

Control and read-out of the HEPD-02 tracking system onboard CSES-02 satellite

The High Energy Particle Detector (HEPD-02) is a payload of the second China Seismo-Electromagnetic Satellite (CSES-02), designed and built by the Italian Limadou collaboration. Its purpose is to detect cosmic rays and trapped particles of radiation belts, in the kinetic energy range 3-100 MeV for electrons, 30-200 MeV for protons. HEPD-02 is the first space detector to use a tracking detector based on Monolithic Active Pixel Sensors (MAPS). The MAPS provides high spatial resolution, low noise, increased robustness, and low production costs. Operating MAPS in space presents a significant challenge due to strict power consumption requirements. To meet such constraints, a custom Tracker Data Acquisition (TDAQ) board and firmware have been designed and implemented, by using a commercial low-power Field Programmable Gate Array (FPGA). This paper addresses the design features of the TDAQ unit, enabling the tracking detector to be operated efficiently, with particular focus on the power consumption performance.

physics.ins-det↗
arXiv2025

The simulation chain for the Terzina Cherenkov telescope on board the NUSES space mission

The Terzina telescope is designed to detect ultra-high energy cosmic rays (UHECRs) and Earth-skimming neutrinos from a 550 km low-Earth orbit (LEO) by observing Cherenkov light emitted by Extensive Air Showers (EAS) in the Earth's atmosphere pointing towards the telescope and in the field of view. In this contribution, a simulation chain for the Terzina telescope on board the NUSES mission will be presented. The chain encompasses all stages of the detection process, from event generation and EAS modelling with CORSIKA and EASCherSim to Geant4-based simulations of the telescope's geometry and optics, followed by modelling of the trigger system and silicon photomultiplier (SiPM) response. The Geant4 module includes the real CAD model of the telescope structure and optical components, with aspherical lenses manually implemented to ensure accurate representation of the optical efficiency and point spread function in Geant4. This comprehensive pipeline, developed using modular C++ code and Python tools for event analysis and reconstruction, produces detailed performance assessments of a telescope operating in a LEO mission but can be adapted for any high altitude Cherenkov telescope, making it a versatile tool for future observatory designs. The possibility of modelling balloons in the atmosphere has also been developed.

astro-ph.IM↗
arXiv2024

The source of the 2017 cosmic ray half-year modulation event

In 2017, as the solar cycle approached solar minimum, an unusually long and large depression was observed in galactic cosmic ray (GCR) protons, detected with the Alpha Magnetic Spectrometer (AMS-02), lasting for the second half of that year. The depression, as seen in the Bartel rotation-averaged proton flux, has the form of a Forbush decrease (FD). Despite this resemblance, however, the cause of the observed depression does not have such a simple explanation as FDs, due to coronal mass ejections (CMEs), typically last for a few days at 1 AU rather than half a year. In this work, we seek the cause of the observed depression and investigate two main possibilities. First, we consider a mini-cycle - a temporary change in the solar dynamo that changes the behavior of the global solar magnetic field and, by this, the modulation of GCRs. Secondly, we investigate the behavior of solar activity, both CMEs and co-rotating/stream interactions regions (C/SIRs), during this period. Our findings show that, although there is some evidence for mini-cycle behavior prior to the depression, the depression is ultimately due to a combination of recurrent CMEs, SIRs and CIRs. A particular characteristic of the depression is that the largest impacts that help to create and maintain it are due to four CMEs from the same, highly active, magnetic source that persists for several solar rotations. This active magnetic source is unusual given the closeness of the solar cycle to solar minimum, which also helps to make the depression more evident.

astro-ph.SR↗
arXiv2021

School reopening should be guided by solid evidence and mitigation measures against Covid-19

The debate on the role of school closures as a mitigation strategy against the spread of Covid-19 is gaining relevance due to emerging variants in Europe. According to WHO, decisions on schools "should be guided by a risk-based approach". However, risk evaluation requires sound methods, transparent data and careful consideration of the context at the local level. We review a recent study by Gandini et al., on the role of school opening as a driver of the second COVID-19 wave in Italy, which concluded that there was no connection between school openings/closures and SARS-CoV-2 incidence. infections. This analysis has been widely commented in Italian media as conclusive proof that "schools are safe". However the study presents severe oversights and careless interpretation of data.

q-bio.PE↗
arXiv2019

Cosmic Ray isotopes measured by AMS02

The measurement of light isotope components in cosmic rays (CR) like3He,2H (D)and6Li are some of the most valuable tools for understanding the propagation of CR in the galaxy and constrain the models that describe it. In this work a new preliminary measurement of3He/4He,6Li/7Li and D/p flux ratios are presented, each obtained from the data of the AMS-02 experiment, along with the measurement of the isotopic component fluxes.

hep-ex↗
arXiv2012

Active Radiation Shield for Space Exploration Missions (ARSSEM)

One of the major issues to be solved is the protection from the effects of ionizing radiation. Exploration mission, lasting two to three years in space, represents a very significant step from the point of view of radiation protection: both the duration (up to 5 times) and the intensity (up to 5 times) of the exposure to radiation are increased at the same time with respect to mission on the ISS reaching and sometime exceeding professional career limits. In this ARSSEM report, after reviewing the physics basis of the issue of radiation protection in space, we present results based for the first time on full physics simulation to understand the interplay among the the various factors determining the dose absorbed by the astronauts during a long duration mission: radiation composition and energy spectrum, 3D particle propagation through the magnetic field, secondary production on the spacecraft structural materia, dose sensitivity of the various parts of the human body. As first application of this approach, we use this analysis to study a new magnetic configuration based on Double Helix coil and exhibiting a number of interesting features which are suited to active shield application. The study also proposes a technology R&D roadmap for active radiation shield development which would match ESA decadal development strategy for human exploration of space.

physics.space-ph↗
arXiv2009

European facilities for accelerator neutrino physics: perspectives for the decade to come

Very soon a new generation of reactor and accelerator neutrino oscillation experiments - Double Chooz, Daya Bay, Reno and T2K - will seek for oscillation signals generated by the mixing parameter theta_13. The knowledge of this angle is a fundamental milestone to optimize further experiments aimed at detecting CP violation in the neutrino sector. Leptonic CP violation is a key phenomenon that has profound implications in particle physics and cosmology but it is clearly out of reach for the aforementioned experiments. Since late 90's, a world-wide activity is in progress to design facilities that can access CP violation in neutrino oscillation and perform high precision measurements of the lepton counterpart of the Cabibbo-Kobayashi-Maskawa matrix. In this paper the status of these studies will be summarized, focusing on the options that are best suited to exploit existing European facilities (firstly CERN and the INFN Gran Sasso Laboratories) or technologies where Europe has a world leadership. Similar considerations will be developed in more exotic scenarios - beyond the standard framework of flavor oscillation among three active neutrinos - that might appear plausible in the occurrence of anomalous results from post-MiniBooNE experiments or the CNGS.

hep-ex↗
arXiv2009

Silicon photomultiplier arrays - a novel photon detector for a high resolution tracker produced at FBK-irst, Italy

A silicon photomultiplier (SiPM) array has been developed at FBK-irst having 32 channels and a dimension of 8.0 x 1.1 mm^2. Each 250 um wide channel is subdivided into 5 x 22 rectangularly arranged pixels. These sensors are developed to read out a modular high resolution scintillating fiber tracker. Key properties like breakdown voltage, gain and photon detection efficiency (PDE) are found to be homogeneous over all 32 channels of an SiPM array. This could make scintillating fiber trackers with SiPM array readout a promising alternative to available tracker technologies, if noise properties and the PDE are improved.

physics.ins-det↗
arXiv2008

A Scintillating Fiber Tracker With SiPM Readout

We present a prototype for the first tracking detector consisting of 250 micron thin scintillating fibers and silicon photomultiplier (SiPM) arrays. The detector has a modular design, each module consists of a mechanical support structure of 10mm Rohacell foam between two 100 micron thin carbon fiber skins. Five layers of scintillating fibers are glued to both top and bottom of the support structure. SiPM arrays with a channel pitch of 250 micron are placed in front of the fibers. We show the results of the first module prototype using multiclad fibers of types Bicron BCF-20 and Kuraray SCSF-81M that were read out by novel 32-channel SiPM arrays from FBK-irst/INFN Perugia as well as 32-channel SiPM arrays produced by Hamamatsu. A spatial resolution of 88 micron +/- 6 micron at an average yield of 10 detected photons per minimal ionizig particle has been achieved.

physics.ins-det↗
arXiv2006

An indirect dark matter search with diffuse gamma rays from the Galactic Centre with the Alpha Magnetic Spectrometer

The detection of non-baryonic dark matter through its gamma-ray annihilation in the centre of our galaxy has been studied. The gamma fluxes according to different models have been simulated and compared to those expected to be observed with the Alpha Magnetic Spectrometer (AMS), during a long-term mission on board of the International Space Station. Under the assumption that the dark matter halo is composed of the lightest, stable supersymmetric particle, the neutralino, the results of the simulations in the framework of mSUGRA models, show that with a cuspy dark matter halo or a clumpy halo, the annihilation gamma-ray signal would be detected by AMS. More optimistic perspectives are obtained with the Anomaly Mediated Supersymmetry Breaking (AMSB) model. The latter leads also to a cosmologically important 6Li abundance. Finally, the discovery potential for the massive Kaluza-Klein dark matter candidates has been evaluated and their detection looks feasible.

astro-ph↗
arXiv2005

AMICA, an astro-mapper for AMS

The Alpha Magnetic Spectrograph (AMS) is a composite particle detector to be accommodated on the International Space Station (ISS) in 2008. AMS is mainly devoted to galactic, charged Cosmic Rays studies, Antimatter and Dark Matter searches. Besides the main, classical physics goals, capabilities in the field of GeV and multi-GeV gamma astrophysics have been established and are under investigation by a number of groups. Due to the unsteadiness of the ISS platform, a star-mapper device is required in order to fully exploit the intrinsic arc-min angular resolution provided by the Silicon Tracker. A star-mapper is conceptually an imaging, optical instrument able to autonomously recognize a stellar field and to calculate its own orientation with respect to an inertial reference frame. AMICA (Astro Mapper for Instruments Check of Attitude) on AMS is responsible for providing real-time information that is going to be used off-line for compensating the large uncertainties in the ISS flight attitude and the structural degrees of freedom. In this paper, we describe in detail the AMICA sub-system and the accommodation/integration issues and the in-flight alignment procedure adopting identified galactic (pulsars) and extragalactic (AGNs) sources.

astro-ph↗
arXiv2002

Astro Particle Physics from Space

We review how some open issues on Astro Particle physics can be studied by space born experiments in a complementary way to what is being done at underground and accelerators facilities

astro-ph↗
arXiv2002

The production of proton and lepton fluxes in near Earth orbit

Substantial fluxes of protons and leptons with energies below the geomagnetic cutoff have been measured by the AMS experiment at altitudes of 370-390 Km, in the latitude interval +/- 51.7 degrees. The production mechanisms of the observed trapped fluxes are investigated in detail by means of the FLUKA Monte Carlo simulation code. All known processes involved in the interaction of the cosmic rays with the atmosphere (detailed descriptions of the magnetic field and atmospheric density, as well as the electromagnetic and nuclear interaction processes) are included in the simulation. The results are presented and compared with the experimental data, indicating good agreement with the observed fluxes. The impact of secondary proton flux on particle production in atmosphere is briefly discussed.

astro-ph↗
arXiv2001

Leptons with E>200 MeV trapped in the Earth's radiation belts

For the first time accurate measurements of electron and positron fluxes in the energy range 0.2-10 GeV have been performed with the Alpha Magnetic Spectometer (AMS) instrument at altitudes of 370-390 Km in the geographic latitude interval +/- 51.7 deg. We present an original analysis of the AMS data, focused on the study of the under-cutoff component of these fluxes, outside the region of the South Atlantic Anomaly (SAA). A separation in quasi-trapped, long lifetime (O(10 s)), and albedo, short life time (O(100 ms)), components is found. The flux maps as a function of the canonical adiabatic variables L, alpha0 are determined in the interval (L,alpha0)=(0.95-3,0-90) for electrons with E less than 10 GeV, and positrons with E less than 3 GeV. The results are compared with existing data at lower energies and in similar L, alpha0 range. The properties of the observed under-cutoff particles are also investigated in terms of their residence times and geographical origin. The resulting distributions are discussed and related to the characteristics of the drift shells observed by AMS.

astro-ph↗
arXiv2001

Recent results from the Alpha Magnetic Spectrometer (AMS) on the STS-91

The Alpha Magnetic Spectrometer (AMS) is a state of the art detector for the extraterrestrial study of matter, antimatter and missing matter. During the ten days long STS-91 precursor flight in may 1998 AMS collected nearly 100 millions of Cosmic Rays on Low Earth Orbit, measuring with high accuracy their composition. We present results on the flux of proton, electron, positron and helium particles in the rigidity region 0.1 to 200 GV . Analysis of the under cutoff spectra indicates the existence of a new type of belts containing high energy particles and characterized by a dominance of positrons versus electrons.

astro-ph↗