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On May 12, 2021 the interplanetary counterpart of the May 9, 2021 coronal mass ejection impacted the Earth’s magnetosphere, giving rise to a strong geomagnetic storm. This work discusses the evolution of the various events linking the solar activity to the Earth’s ionosphere with special focus on the effects observed in the circumterrestrial environment. We investigate the propagation of the interplanetary coronal mass ejection and its interaction with the magnetosphere - ionosphere system in terms of both magnetospheric current systems and particle redistribution, by jointly analysing data from interplanetary, magnetospheric, and low Earth orbiting satellites. The principal magnetospheric current system activated during the different phases of the geomagnetic storm is correctly identified through the direct comparison between geosynchronous orbit observations and model predictions. From the particle point of view, we have found that the primary impact of the storm development is a net and rapid loss of relativistic electrons from the entire outer radiation belt. Our analysis shows no evidence for any short-term recovery to pre-storm levels during the days following the main phase. Storm effects also included a small Forbush decrease driven by the interplay between the interplanetary shock and subsequent magnetic cloud arrival.

Introduction: This study aims at defining through a retrospective evaluation, the clinical parameters affecting the clinical course and consequently the management of patients presenting with cervicofacial abscesses. Methodology: A total of 394 patients diagnosed with abscess at the University of Sassari Otorhinolaryngology Division between 2009 and 2017 were included; among these, eleven patients were diagnosed with necrotizing fasciitis. Personal and clinical parameters including the LRINEC score and the medical and/or surgical treatment used were analyzed for each patient. The most frequently affected site was the peritonsillar space (76.9%), followed by the parapharyngeal space. Results: Mean age was 41(±17) years, the male population was slightly overrepresented (68%). An average of 6 (±7) days of hospitalization duration was recorded. The mortality rate was confirmed to be relatively low (1/349 patients) and was reported only in one patient diagnosed with necrotizing fasciitis (1/11). Conclusion: Diagnosis, correct clinical definition and early medical-surgical treatment of neck abscesses were crucial to reduce complications; LRNEC score, C-reactive protein, glycemia and creatininemia proved to be reliable prognostic indicators of difficult patient management and risk of complications.

This contribution describes the Trigger board of the High-Energy Particle Detector, which will be placed onboard the second China Seismo-Electromagnetic Satellite for CSES-Limadou mission. This mission will monitor variations in ionospheric parameters that are supposed to be related to earthquakes. The first satellite is already in orbit and the second one will be launched in 2023. The HEPD detector will be composed by a tracker made of CMOS sensors (ALPIDE sensors), followed by two segmented planes of plastic scintillators used for trigger signals generation. The actual calorimeter will be composed by twelve planes of plastic scintillator and two segmented planes of an inorganic scintillator called LYSO. The calorimeter is surrounded by five scintillator planes used as a veto system. All the scintillators are coupled with PMTs, whose signals are acquired and digitized by the Trigger board, that also implements the trigger system for the whole apparatus. The ongoing work on the Trigger board consists in the design of both the hardware and the firmware used for the communication with the other boards of the detector, power managing, and the interfacing with the ASIC used for PMTs’ readout. Eventually the Trigger board will be tested to verify its functionalities and its compliance with the HEPD design specifications. Next developments are the integration of the Trigger board with the other systems on the detector and the environmental testing of the whole system.

Still today vaguely defined, the South Atlantic Anomaly (SAA) is the vastgeographic region where the Earth’s magnetic field is weakest relative to anideal Earth-centered dipole field, and the inner radiation belt comes closestto the planet. Nonetheless it represents a major concern to the space sciencecommunity, since the local reduced magnetic intensity often results in satelliteoutages and radiation hazard to humans, especially in geomagnetically disturbedperiods.Since 1958, relentless investigation of the various morphological and dynamicfeatures of the SAA has been taking place, robustly relying on field, plasma andparticle measurements from Low-Earth-Orbit (LEO) satellites since the late1970s.New readings provided by magnetometers operating at LEO altitudes show that,within the past decade, an apparent second center of minimum field intensityhas begun to be clearly resolved southwest of Africa, suggesting a possible rapidsplitting of the SAA into two cells. In addition to magnetic determinations, thetracking of fluxes of sub-MeV electrons that are lost to the atmosphere whendrifting into the SAA due to its increased bounce loss cone, offers a specularview of the same phenomenon. This multi-messenger approach from differentplatforms is best suited to catch fine details of the splitting.Directly stemming from the data-adaptive Empirical Mode Decomposition (EMD)developed at NASA in the 1990s for the analysis of non-stationary signals, theFast Iterative Filtering (FIF) class of signal mode decompositions is recentlytaking center stage due to enhanced rigorous formalization in terms of con-vergence and stability. Multidimensional and Multivariate FIF (MMFIF) is abrand-new extension that handles multidimensional and multichannel datasets.The application of MMFIF techniques to magnetic-field and particle data froman ensemble of LEO satellites has allowed us to best characterize the dynamicevolution of the SAA lobes in the 2010s, and compare it to analogous data inthe literature from the previous decades.

We present a study of the solar-cycle variations of >80 MeV proton flux intensities in the lower edge of the inner radiation belt, based on the measurements of the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) mission. The analyzed data sample covers an ~8 year interval from 2006 July to 2014 September, thus spanning from the decaying phase of the 23rd solar cycle to the maximum of the 24th cycle. We explored the intensity temporal variations as a function of drift shell and proton energy, also providing an explicit investigation of the solar-modulation effects at different equatorial pitch angles. PAMELA observations offer new important constraints for the modeling of low-altitude particle radiation environment at the highest trapping energies., accepted for publication in the Astrophysical Journal Letters

We present a study of the east-west anisotropy of trapped-proton fluxes in low-Earth orbit based on the measurements of the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) experiment. The differential intensities of eastward- and westward-traveling protons detected in the South Atlantic Anomaly region were estimated as a function of equatorial pitch angle and drift shell, for six energy bins between 80 MeV and 2 GeV. We found that, as a consequence of the strong atmospheric gradient coupled with the large gyroradius in this energy range, the intensities of eastward fluxes exceed those of westward fluxes by a factor of ∼10-20. However, the reported directional asymmetry also depends on the sign of the local flux gradient, resulting in more intense westward fluxes beyond the radial distances where the inner belt peaks. PAMELA observations can be used to improve the description of the near-Earth radiation environment at lowest altitudes and highest trapping energies, where current theoretical and empirical models are affected by the largest uncertainties.

On 25 August 2018, a G3-class geomagnetic storm reached the Earth’s magnetosphere, causing a transient rearrangement of the charged particle environment around the planet, which was detected by the High-Energy Particle Detector (HEPD) on board the China Seismo-Electromagnetic Satellite (CSES-01). We found that the count rates of electrons in the MeV range were characterized by a depletion during the storm’s main phase and a clear enhancement during the recovery caused by large substorm activity, with the key role played by auroral processes mapped into the outer belt. A post-storm rate increase was localized at L-shells immediately above ∼3 and mostly driven by non-adiabatic local acceleration caused by possible resonant interaction with low-frequency magnetospheric waves.

Precise time-dependent measurements of the Z = 2 component in the cosmic radiation provide crucial information about the propagation of charged particles through the heliosphere. The PAMELA experiment, with its long flight duration (2006 June 15-2016 January 23) and the low energy threshold (80 MeV/n) is an ideal detector for cosmic-ray solar modulation studies. In this paper, the helium nuclei spectra measured by the PAMELA instrument from 2006 July to 2009 December over a Carrington rotation time basis are presented. A state-of-the-art three-dimensional model for cosmic-ray propagation inside the heliosphere was used to interpret the time-dependent measured fluxes. Proton-to-helium flux ratio time profiles at various rigidities are also presented in order to study any features that could result from the different masses and local interstellar spectra shapes.

The China Seismo-Electromagnetic Satellite (CSES) is a scientific mission devoted to the study of electromagnetic, plasma and particle perturbations of atmosphere, ionosphere, magnetosphere and Van Allen belts, with special focus on potential correlation between transient phenomena and high magnitude earthquakes. For this purpose, CSES comprises nine payloads, including the High-Energy Particle Detector (HEPD), developed by the Italian CSES-Limadou collaboration. HEPD is devoted to the observations of high energy Cosmic Rays in the range 3-200 MeV, measuring both the incident direction and the energy of the incoming particle, discriminating its nature (electrons, protons). The satellite, launched on February 2, 2018 from the Jiuquan Satellite Launch Center (Inner Mongolia, China), underwent the commissioning phase (February-July 2018) during which several configurations were set in order to define the optimal operational conditions throughout the foreseen 5-year mission duration. This paper describes the HEPD instrument, its energy calibration and first in-flight performances, with special emphasis on the calorimeter and trigger subsystems, demonstrating its sensitivity to different particle populations.

The radiation belts in the Earth’s magnetosphere pose a hazard to satellite systems and spacecraft missions (both manned and unmanned), heavily affecting payload design and resources, thus resulting in an impact on the overall mission performance and final costs. The NASA AE9/AP9/SPM radiation models for energetic electrons, protons, and plasma provide useful information on the near-Earth environment, but they are still incomplete as to some features and, for some energy ranges, their predictions are not based on a statistically sufficient sample of direct measurements. Therefore, it is of the upmost importance to provide new data and direct measurements to improve their output. In this work, the AP9 model is applied to the China Seismo-Electromagnetic Satellite (CSES-01) orbit to estimate the flux of energetic protons over the South Atlantic Anomaly during a short testing period of one day, 1 January 2021. Moreover, a preliminary comparison with proton data obtained from the High-Energy Particle Detector (HEPD) on board CSES-01 is carried out. This estimation will serve as the starting ground for a forthcoming complete data analysis, enabling extensive testing and validation of current theoretical and empirical models.

The High-Energy Particle Detector (HEPD) is one of the payloads of the CSES space mission. The CSES (China Seismo-Electromagnetic Satellite) mission will investigate the structure and the dynamic of the topside ionosphere, will monitor electric and magnetic field and high energy particle fluctuations, searching for their correlations with the geophysical activity, in order to contribute to the monitoring of earthquakes from space. The HEPD is built by the Italian collaboration and has different goals. It will study the temporal stability of the inner Van Allen radiation belts, the precipitation of trapped particles in the atmosphere and the low energy component of the cosmic rays (5 - 100 MeV for electrons and 15 - 300 MeV for protons). Here is presented a study of the performance of the apparatus to separate electrons and protons and identify nuclei up to iron.

The High-Energy Particle Detector (HEPD) is a range-calorimeter for the near-Earth measurement of electrons, protons and light nuclei fluxes up to few hundreds of MeV. HEPD will fly on board of the China Seismo-Electromagnetic Satellite (CSES), scheduled to be launched in July/August 2017. This mission will investigate possible correlations between geomagnetic properties (electromagnetic wave emissions, plasma properties and particle fluxes in the ionosphere and magnetosphere) and seismic events. The study of the solar-terrestrial environment, Coronal Mass Ejections (CMEs), Solar Energetic Particles (SEPS) events and low-energy cosmic rays are also within the scientific objectives of this mission. A detailed description of the HEPD and its characteristics will be reported.

The study of the Van Allen belts temporal stability is among the main objectives of the China Seismo-Electromagnetic Satellite (CSES) space mission, as well as the study of other electromagnetic disturbances with possible seismic origin. In parallel to this, the CSES mission will address issues of heliospheric and magnetospheric physics, by measuring the cosmic radiation around the Earth. The CSES satellite, developed by a Chinese-Italian collaboration, will be launched in the first half of 2017 and inserted into a circular Sun-synchronous orbit with 98° inclination and 500 km altitude. The expected lifetime is 5 years. CSES hosts several instruments on board: 2 magnetometers, an electric field detector, a plasma analyser, a Langmuir probe and a High-Energy Particle Detector (HEPD). The HEPD detector, responsibility of the Italian side of the CSES collaboration, will measure electrons (3 - 100 MeV) and protons (30 - 300 MeV) along CSES orbit. It consists of a segmented layer of plastic scintillators for the trigger and a calorimeter constituted by a tower of plastic scintillator counters and a LYSO plane. The direction of the incident particle is provided by two planes of double-side silicon micro-strip detectors placed in front of the trigger. Topic of this talk is the technical description of the HEPD and its main characteristics.

CSES-01 (China Seismo-Electromagnetic Satellite) is a space mission dedicated to the study of the ionospheric environment, searching for disturbances that can be correlated to seismic activity. For this reason, the satellite is equipped with several instruments to monitor various physical parameters including the Earth's electric and magnetic field, ionospheric plasma principal parameters (i.e. density, temperature, and ions composition) and high energy particle flux fluctuations. The High Energy Particle Detector (HEPD), built by the Italian CSES-Limadou collaboration, is designed to detect mostly electrons in the energy range between 3 MeV and 100 MeV and protons in the energy range between 30 MeV and 300 MeV. The detector is composed of a tracking system, a segmented layer of plastic scintillator (used for the trigger), a range calorimeter and a veto system. After CSES-01 launch (February 2, 2018), the apparatus underwent the commissioning phase where its configuration was adjusted in order to guarantee optimal operational conditions in the space environment. Now the satellite is in stable data-taking mode. In this work a description of the HEPD detector will be reported, focusing on the results of the electron and proton test beam calibrations. In addition, a particular relevance will be given to the presentation of the HEPD in-flight performance, such as its good capability in particle identification. The high statistic collected by HEPD, thanks to its large acceptance window, makes it perfectly suitable for the investigation of fluctuations in the charged particle fluxes.

The High-Energy Particle Detector (HEPD) is one of the payloads of the CSES space mission, built by the Italian “Limadou” collaboration. It will study the temporal stability of the inner Van Allen radiation belts, the precipitation of trapped particles in the atmosphere and the low energy component of the cosmic rays (5 - 100 MeV for electrons and 15 - 300 MeV for protons). Results of the test beams held at the Beam Test Facility of the INFN National Laboratory of Frascati, for electrons, and at the Proton Cyclotron of Trento, for protons, will be presented. The performance of the apparatus both on the energy reconstruction and in the lepton/hadron separation will be shown.

CSES-01 (China Seismo-Electromagnetic Satellite) is a mission developed by CNSA (Chinese National Space Administration) and ASI (Italian Space Agency) to investigate the near-Earth electromagnetic, plasma and particle environment, focusing on the disturbances of the ionosphere-magnetosphere transition region. In this framework, the Italian High Energy Particle Detector (HEPD) on board CSES-01, is an advanced detector based on a tower of scintillators and a silicon tracker that provide good energy resolution as well as a wide angular acceptance for electrons of 3-100 MeV, protons of 30-200 MeV and light nuclei (up to Oxygen). The very good capabilities in both detection and discrimination of particles make the detector well suited for space-weather purposes; indeed HEPD is able to continuously monitor the magnetospheric environment with high precision and stability in time. Turbulent conditions in the near-Earth environment translate into modification of particles and magnetic/electric measurements at different time-scales. In this work, the data-analysis techniques and some preliminary results concerning the study of different proton populations encountered along CSES-01 orbit (galactic cosmic rays, re-entrant albedo etc.) are presented.

The High-Energy Particle Detector (HEPD) is one of the payloads of the CSES space mission. The HEPD is built by the Italian Limadou collaboration and has different goals. It will study the temporal stability of the inner Van Allen radiation belts, the precipitation of trapped particles in the atmosphere and the low energy component of the cosmic rays (5-100 MeV for electrons and 15 - 300 MeV for protons). It has been tested at the Beam Test Facility of the INFN National Laboratory of Frascati, for electrons, and at the Proton Cyclotron of Trento, for protons. Here is presented a study of the performance of the apparatus to separate electrons and protons and identify nuclei up to iron.