ESAF: Full Simulation of Space-Based Extensive Air Showers Detectors

Future detection of Extensive Air Showers (EAS) produced by Ultra High Energy Cosmic Particles (UHECP) by means of space based fluorescence telescopes will open a new window on the universe and allow cosmic ray and neutrino astronomy at a level that is virtually impossible for ground based detectors. In this paper we summarize the results obtained in the context of the EUSO project by means of a detailed Monte Carlo simulation of all the physical processes involved in the fluorescence technique, from the Extensive Air Shower development to the instrument response. Particular emphasis is given to modeling the light propagation in the atmosphere and the effect of clouds. Main results on energy threshold and resolution, direction resolution and Xmax determination are reported. Results are based on EUSO telescope design, but are also extended to larger and more sensitive detectors.Comment: 38 pages, 48 figures Corrected typos. Changed content. Added figure

Detection of the Cherenkov light diffused by Sea Water with the ULTRA Experiment

The study of Ultra High Energy Cosmic Rays represents one of the most challenging topic in the Cosmic Rays and in the Astroparticle Physics fields. The interaction of primary particles with atmospheric nuclei produces a huge Extensive Air Shower together with isotropic emission of UV fluorescence light and highly directional Cherenkov photons, that are reflected/diffused isotropically by the impact on the Earth's surface or on high optical depth clouds. For space-based observations, detecting the reflected Cherenkov signal in a delayed coincidence with the fluorescence light improves the accuracy of the shower reconstruction in space and in particular the measurement of the shower maximum, giving a strong signature for discriminating hadrons and neutrinos, and helping to estimate the primary chemical composition. Since the Earth's surface is mostly covered by water, the ULTRA (UV Light Transmission and Reflection in the Atmosphere)experiment has been designed to provide the diffusing properties of sea water, overcoming the lack of information in this specific field. A small EAS array, made up of 5 particle detectors, and an UV optical device, have been coupled to detect in coincidence both electromagnetic and UV components. The detector was in operation from May to December, 2005, in a small private harbor in Capo Granitola (Italy); the results of these measurements in terms of diffusion coefficient and threshold energy are presented here.Comment: 4 pages, 3 figures, PDF format, Proceedings of 30th ICRC, International Cosmic Ray Conference 2007, Merida, Yucatan, Mexico, 3-11 July 200

Requirements and simulation study of the performance of EUSO as external payload on board the International Space Station

The "Extreme Universe Space Observatory - EUSO" has been conceived as the first Space mission devoted to the investigation of Ultra High Energy Cosmic Ray, using the Earth's atmosphere as a giant detector. The scientific objectives of the experiment are to observe the UHECR spectrum above the GZK energy, with an improvement of one order of magnitude in the statistics of collected events with respect to the existing experiments, in such a way to study the source distribution in a full sky survey, as well as to open the channel (set a confidence limit) on the neutrino astronomy in this energy range. Supposed to be accommodated as external payload on board the International Space Station, EUSO phase A study has been positively completed in July 2004. Nowadays, due to funding problems of the Space Agencies involved in the project, EUSO is currently on hold. Nevertheless, as result of an end-to-end simulation approach, we summarize here the expected scientific performance coming out from the phase A, as well as the expected improvements in the technical performance of the EUSO Instrument to be achieved during Phase B, in order to fulfil the scientific objectives posed as goal of the experiment

Results from the ULTRA experiment in the framework of the EUSO project

The detection of Cerenkov light from EAS in a delayed coincidence with fluorescence light gives a strong signature to discriminate protons and neutrinos in cosmic rays. For this purpose, the ULTRA experiment has been designed with 2 detectors: a small EAS array (ETscope) and an UV optical device including wide field (Belenos) and narrow field (UVscope) Cerenkov light detectors. The array measures the shower size and the arrival direction of the incoming EAS, while the UV devices, pointing both to zenith and nadir, are used to determine the amount of direct and diffused coincident Cerenkov light. This information, provided for different diffusing surfaces, will be used to verify the possibility of detecting from Space the Cerenkov light produced by UHECRs with the EUSO experiment, on board the ISS

Influenza vaccine hesitancy in patients with multiple sclerosis: A monocentric observational study

Background. The so-called ‘vaccine hesitancy’ still represents a common phenomenon that undermines the effectiveness of vaccination campaigns. In 2020, the Italian Medicines Agency recommended to bring forward the flu vaccination campaign, whose importance was also emphasized for patients with Multiple Sclerosis (MS). We aimed to assess vaccination behavior in patients with MS to prepare for the upcoming SARS-CoV-2 vaccination challenge. Methods. This is an observational study carried out in one MS clinical Centre that enrolled all MS patients who were eligible for any of the flu vaccines recommended by the Italian medicines Agency. Results. 194 patients were enrolled. Patients’ mean age was 43.9 years and 66% were female. Comorbidities, mainly represented by non-autoimmune diseases, were identified in 52% of patients. Almost all patients were receiving a DMT during the study period, mainly dimethyl fumarate, natalizumab, teriflunomide, and interferon. Out of 194 patients, 58.2% accepted to be vaccinated. No statistically significant differences were found, except for the use of natalizumab, which was higher among vaccinated patients. Conclusion. The results of our study emphasize the importance of education and communication campaigns addressed both to healthcare providers and patients with MS, especially considering that MS patients are currently receiving COVID-19 vaccinations

Diffused Cerenkov light measurements for the EUSO project

International audienceThe aim of the EUSO (Extreme Universe Space Observatory) experiment is to measure from space the fluorescent light produced by the interaction of Extreme Energy Cosmic Rays (EECRs) with the Earth atmosphere. Besides the fluorescent signal, a huge amount of Čerenkov photons is emitted in a narrow cone hitting the Earth surface, where it is partially diffused. The detection of this diffused signal, in a delayed coincidence with the fluorescent signal, allows the absolute positioning of the EECR track, while the knowledge of the diffusing properties of the surface gives an independent indication of the shower energy. Measuring simultaneously on ground the electromagnetic component, the direct Čerenkov light, and the diffused Čerenkov light over different surfaces, we aim to characterize the emitted signal as a function of the energy and the arrival direction of the Extensive Air Shower (EAS), and to evaluate its possible detection from space. This is implemented by the ULTRA (UvLight Transmission and Reflection in the Atmosphere) experiment composed by a small EAS array and a UltraViolet (UV) telescope. The experimental setups used in the first runs at sea level and at 1970 m a.s.l. are described and the first preliminary results are presented

Extensive Air Showers and Diffused Cerenkov Light Detection: the ULTRA Experiment

The Uv Light Transmission and Reflection in the Atmosphere (ULTRA) experiment has been designed to provide quantitative measurements of the backscattered Cherenkov signal associated to the Extensive Air Showers (EAS) at the impact point on the Earth surface. The knowledge of such information will test the possibility to detect the diffused Cherenkov light spot from space within the Ultra high-energy cosmic ray observation. The Cherenkov signal is necessary to give an absolute reference for the track, allowing the measurement of the shower maximum and easing the separation between neutrino and hadronic showers. In this paper we discuss the experimental set-up with detailed information on the detection method; the in situ and laboratory calibrations; the simulation of the expected detector response and finally the preliminary results on the detector performance