The EUSO-TA ground-based detector: results and perspectives

EUSO--TA is a ground-based telescope installed in 2013 in the Black Rock Mesa Telescope Array (BRM-TA) site, operating with 2.5$\mu$s time resolution to observe the night sky in the UV range. The optical system contains two 1m$^2$ Fresnel lenses providing to the telescope a field of view of $11^\circ \times 11^\circ$. Signals are focused on the Photo Detector Module (PDM), with the focal surface composed of 36 Hamamatsu Multi-Anode PhotoMultiplier Tubes (MAPMTs), with 64 pixels/anodes each. The telescope is housed in a shed in front of the BRM-TA fluorescence detectors, and it is viewing towards azimuth $\sim307^\circ$. The main aim of the experiment is to validate the design of the JEM-EUSO detectors and firmware with the final goal of observing ultra-high-energy cosmic rays (UHECRs) from space. Since the first installation of the EUSO-TA detector, 9 UHECR events have been detected and confirmed by comparison with TA observations. The night-sky UV background in different conditions, signals from stars and meteors have been measured, and anthropogenic signals, such as calibration lasers or planes. In 2019 an upgrade of the detector to a EUSO-TA2 version began, with a Covid brake till 2022. The new configuration will allow for more frequent and specialized observations. In this work, we present the status and perspectives of the EUSO-TA experiment, including a discussion of recently obtained results

Calibration and testing of the JEM-EUSO detectors using stars observed in the UV band

The JEM-EUSO program is focused on observations of Ultra High Energy Cosmic Rays (UHECRs) from space. For this purpose, a series of detectors based on multi-anode photomultiplier tubes with a time resolution of the order of $\mu$s have been developed. The detectors work in the UV band to search for ultra-fast signals produced in the Earth's atmosphere during an Extensive Air Shower (EAS) development. Since 2014, various signals have been detected by ground-, ballon- and space-based detectors. A single photodetector module consists of a focal surface with a matrix of 36 multi-anode photomultiplier tubes containing 2304 pixels. The detector's structure allows probing it during the mission if a point-like source emitting in a UV band is in the field of view. In this work, we present the idea and results of calibration of the JEM--EUSO detectors using signals from stars registered during sky observations from the ground. Registered signals can be used for the absolute calibration of the detectors and for testing the detector condition during observations. The presented analysis is based on the data taken by the EUSO-TA and EUSO-TA2 experiments

Elastic scattering in geometrical model

The experimental data on proton–proton elastic and inelastic scattering emerging from the measurements at the Large Hadron Collider, calls for an efficient model to fit the data. We have examined the optical, geometrical picture and we have found the simplest, linear dependence of this model parameters on the logarithm of the interaction energy with the significant change of the respective slopes at one point corresponding to the energy of about 300 GeV. The logarithmic dependence observed at high energies allows one to extrapolate the proton–proton elastic, total (and inelastic) cross sections to ultra high energies seen in cosmic rays events which makes a solid justification of the extrapolation to very high energy domain of cosmic rays and could help us to interpret the data from an astrophysical and a high energy physics point of view.Funded by SCOAP

Neural Network Based Approach to Recognition of Meteor Tracks in the Mini-EUSO Telescope Data

Mini-EUSO is a wide-angle fluorescence telescope that registers ultraviolet (UV) radiation in the nocturnal atmosphere of Earth from the International Space Station. Meteors are among multiple phenomena that manifest themselves not only in the visible range but also in the UV. We present two simple artificial neural networks that allow for recognizing meteor signals in the Mini-EUSO data with high accuracy in terms of a binary classification problem. We expect that similar architectures can be effectively used for signal recognition in other fluorescence telescopes, regardless of the nature of the signal. Due to their simplicity, the networks can be implemented in onboard electronics of future orbital or balloon experiments.Comment: 15 page

Extrapolation of proton-proton cross section to cosmic ray energies using geometrical model

We present a new parameterization of the hadronic matter distribution in the geometrical picture of elastic scattering. Our model contains four free energy-dependent parameters that allows us to propose a better description of differential elastic cross section data measured in accelerator experiments from ISR to LHC energies. A simple linear dependence of all parameters on the logarithm of energy above √_s = 300 GeV allows an extrapolation of elastic, inelastic and total proton-proton cross sections to ultra high energies seen in cosmic rays. Results of the extrapolation are in agreement with cross sections presented by ground-based cosmic ray experiments like AUGER or Telescope Array. Our parameterization also shows agreement with “BEL behaviour” of proton

EAS longitudinal development distribution parameters for different extrapolations of the nuclei intaraction cross section to the very high energy domain

Determination of the primary particle mass using air fluorescence or a Cherenkov detector array is one of the most difficult task of experimental cosmic ray studies. The information about the primary particle mass is a compound of the produced particle multiplicity, inelasticity, interaction cross-section and many other parameters, thus it is necessary to compare registered showers with sophisticated Monte-Carlo simulation results. In this work we present results of the studies of at least three possible ways of extrapolating proton- Nucleus and Nucleus-Nucleus cross sections to cosmic ray energies based on the Glauber theory. They are compared with experimental accelerator and cosmic ray data for the proton-air cross section. We also present results of the EAS development with the most popular high-energy interaction models adopted in the CORSIKA program with our cross section extrapolations. The average position of the shower maximum and the width of its distribution are compared with experimental data and some discussion is given

Extrapolation of proton-proton cross section to cosmic ray energies using geometrical model

We present a new parameterization of the hadronic matter distribution in the geometrical picture of elastic scattering. Our model contains four free energy-dependent parameters that allows us to propose a better description of differential elastic cross section data measured in accelerator experiments from ISR to LHC energies. A simple linear dependence of all parameters on the logarithm of energy above √_s = 300 GeV allows an extrapolation of elastic, inelastic and total proton-proton cross sections to ultra high energies seen in cosmic rays. Results of the extrapolation are in agreement with cross sections presented by ground-based cosmic ray experiments like AUGER or Telescope Array. Our parameterization also shows agreement with “BEL behaviour” of proton

EAS longitudinal development distribution parameters for different extrapolations of the nuclei intaraction cross section to the very high energy domain

Determination of the primary particle mass using air fluorescence or a Cherenkov detector array is one of the most difficult task of experimental cosmic ray studies. The information about the primary particle mass is a compound of the produced particle multiplicity, inelasticity, interaction cross-section and many other parameters, thus it is necessary to compare registered showers with sophisticated Monte-Carlo simulation results. In this work we present results of the studies of at least three possible ways of extrapolating proton- Nucleus and Nucleus-Nucleus cross sections to cosmic ray energies based on the Glauber theory. They are compared with experimental accelerator and cosmic ray data for the proton-air cross section. We also present results of the EAS development with the most popular high-energy interaction models adopted in the CORSIKA program with our cross section extrapolations. The average position of the shower maximum and the width of its distribution are compared with experimental data and some discussion is given