Detection Of Extensive Air Showers Research Articles

Proton-air interactions at ultra-high energies in muon-depleted air showers with different depths

The hardness of the energy spectrum of neutral pions produced in proton-air interactions at ultra-high energies, above 1018 eV, is constrained by the steepness of the shower-to-shower distribution of the number of muons in muon-depleted extensive air showers.In this work, we find that this steepness, quantified by the parameter Λμ, evolves with the depth of the shower maximum, Xmax, assuming a universal value for shallow showers and an enhanced dependence on the high-energy hadronic interaction model for deep showers. We show that Xmax probes the so-called hadronic activity of the first proton-air interaction, thus allowing direct access to the energy spectrum of neutral pions in different regions of its kinematic phase space.We verify that the unbiased measurement of Λμ is possible for realistic mass composition expectations. Finally, we infer that the statistical precision in Λμ required to distinguish between hadronic interaction models can be achieved in current extensive air shower detectors, given their resolution and exposure.

Atmospheric muons measured with the KM3NeT detectors in comparison with updated numeric predictions

The measurement of the flux of muons produced in cosmic ray air showers is essential for the study of primary cosmic rays. Such measurements are important in extensive air shower detectors to assess the energy spectrum and the chemical composition of the cosmic ray flux, complementary to the information provided by fluorescence detectors. Detailed simulations of the cosmic ray air showers are carried out, using codes such as CORSIKA, to estimate the muon flux at sea level. These simulations are based on the choice of hadronic interaction models, for which improvements have been implemented in the post-LHC era. In this work, a deficit in simulations that use state-of-the-art QCD models with respect to the measurement deep underwater with the KM3NeT neutrino detectors is reported. The KM3NeT/ARCA and KM3NeT/ORCA neutrino telescopes are sensitive to TeV muons originating mostly from primary cosmic rays with energies around 10 TeV. The predictions of state-of-the-art QCD models show that the deficit with respect to the data is constant in zenith angle; no dependency on the water overburden is observed. The observed deficit at a depth of several kilometres is compatible with the deficit seen in the comparison of the simulations and measurements at sea level.

Effects of thunderstorms electric field on secondary photons of cosmic ray at large high altitude air shower observatory

Large high altitude air shower observatory (LHAASO) is a complex of extensive air shower (EAS) detector arrays, located on the Mt. Haizi (29°21' N, 100°08' E) at an altitude of 4410 m a. s. l., Daocheng, Sichuan Province, China. The information about primary cosmic rays can be obtained by using data from secondary particles measured at LHAASO, with photons make up the majority among these secondary particles. During thunderstorms, the atmospheric electric field can affect secondary charged particles (mainly positrons and electrons), thus changing the information of photons on the ground. In this work, Monte Carlo simulations are performed to investigate the effects of near-ground thunderstorm electric fields on cosmic ray secondary photons at LHAASO. A simple model with a vertical and uniform atmospheric electric field in a layer of atmosphere is used in our simulations. During thunderstorms, the number and energy of photons are found to significantly change and strongly depend on the electric field strength. In a field of –1000 V/cm (below the threshold of the relativistic runaway electron avalanche (RREA) process), the number of photons is increased by 23%. Also, the spectrum of photons softens, and the increased number of photons with energy less than 2 MeV exceeds 29%. In an electric field of –1700 V/cm (above the threshold of the RREA process), the number of photons experiences exponential growth, with an increase of 279%. The spectrum of photons becomes softer than that at –1000 V/cm, and the increased number with energy less than 2 MeV is more than 361%. It is consistent with the theory of RREA. For these phenomena of photons at LHAASO, the main factor is that the number of positrons and electrons are increased due to the acceleration of negative electric field on electrons, with increase of 65% in –1000 V/cm and 992% in –1700 V/cm, and the spectrum of positrons and electrons soften. Newborn free positrons/electrons may undergo bremsstrahlung and deposit part of their energy into photons, causing the change of number and energy of photons to follow roughly the same pattern as positrons and electrons. The simulation results can provide the information for understanding the variations of the data detected by LHAASO during thunderstorms and the acceleration mechanisms of secondary charged particles caused by an atmospheric electric field.

Calibration of the NEVOD-EAS array for detection of extensive air showers

In this paper we discuss the calibration of the NEVOD-EAS array which is a part of the Experimental Complex NEVOD, as well as the results of studying the response features of its scintillation detectors. We present the results of the detectors energy calibration, performed by comparing their response to different types of particles obtained experimentally and simulated with the Geant4 software package, as well as of the measurements of their timing resolution. We also discuss the results of studies of the light collection non-uniformity of the NEVOD-EAS detectors and of the accuracy of air-shower arrival direction reconstruction, which have been performed using other facilities of the Experimental Complex NEVOD: the muon hodoscope URAGAN and the muon tracking detector DECOR.

The full coverage approach to the detection of Extensive Air Showers

A shower array exploiting the full coverage approach with a high segmentation of the readout allow to image the front of atmospheric showers with unprecedented resolution and detail. The grid distance determines the energy threshold (small energy showers are lost in the gap between detectors) and the quality of the shower sampling. Therefore, this experimental solution is needed to detect showers with a threshold in the 100 GeV range. The full coverage approach has been exploited in the ARGO-YBJ experiment. In this contribution we will summarise the advantages of this technique and discuss possible applications in new wide field of view detectors.

A Catalog of the Highest-energy Cosmic Rays Recorded during Phase I of Operation of the Pierre Auger Observatory

A catalog containing details of the highest-energy cosmic rays recorded through the detection of extensive air showers at the Pierre Auger Observatory is presented with the aim of opening the data to detailed examination. Descriptions of the 100 showers created by the highest-energy particles recorded between 2004 January 1 and 2020 December 31 are given for cosmic rays that have energies in the range 78–166 EeV. Details are also given on a further nine very energetic events that have been used in the calibration procedure adopted to determine the energy of each primary. A sky plot of the arrival directions of the most energetic particles is shown. No interpretations of the data are offered.

Performance of the RF Detectors of the Astroneu Array

Since 2014, the university campus of Hellenic Open University (HOU) has hosted the Astroneu array, which is dedicated to the detection of extensive air showers (EAS) induced by high-energy cosmic rays (CR). The Astroneu array incorporates 9 large particle scintillation detectors and 6 antennas sensitive to the radio frequency (RF) range 1–200 MHz. The detectors are adjusted in three autonomous stations operating in an environment with a strong electromagnetic background. As shown by previous studies, EAS radio detection in such environments is possible using innovative noise rejection methods, as well as advanced analysis techniques. In this work, we present the analysis of the collected radio data corresponding to an operational period of approximately four years. We present the performance of the Astroneu radio array in reconstructing the EAS axis direction using different RF detector geometrical layouts and a technique for the estimation of the shower core by comparing simulation and experimental data. Moreover, we measure the relative amplitudes of the two mechanisms that give rise to RF emission (the Askaryan effect and geomagnetic emission) and show that they are in good agreement with previous studies as well as with the simulation predictions.

Preface

AtmoHEAD (ATmospheric Monitoring for High Energy Astroparticle Detectors) is a periodic 3-days international workshop on the influence of the atmosphere on high-energy cosmic-ray and gamma-ray astroparticle detectors. The 2022 edition is focused on atmospheric monitoring and on the detection and study of events related to atmospheric electricity. The event follows the tradition of previous AtmoHEAD conferences - AtmoHEAD 2013 in Saclay, 2014 in Padova, 2016 in Olomouc and 2018 in Anacapri.The atmosphere is an integral component of many high-energy astroparticle detectors. These include Imaging Atmospheric Cherenkov Telescopes (IACTs) and ground or space based cosmic-ray extensive air shower detectors. All these observatories use the atmosphere as a giant calorimeter where cosmic rays and gamma rays deposit their energy and initiate extensive air showers; it is also the medium through which the resulting Cherenkov and Fluorescence light propagates, and through which it is attenuated and scattered before reaching the detectors. Clearly, a precise and quantitative monitoring of the atmospheric aerosol and molecular conditions are mandatory for an accurate reconstruction of the detected events. Moreover, in the last years there is a growing interest in the detection of electrical phenomena (ELVES, TGFs, ...) developed in atmosphere with high-energy astroparticle detectors, which represent a unique opportunity to study the characteristics of these events with large statistics and precision.New and common monitoring and calibration instruments including lidars, distant laser facilities, cloud monitors, all sky cameras, sun/moon photometers, satellite observations, lightning sensors, as well as simulations, are among the most important tools of these observatories.These online workshop proceedings are grouped in two main sections, Atmospheric Characterization and Atmospheric Electricity and focus on the state-of-the-art and future perspectives of techniques and instruments.Some more detail on the topics treated in the workshop :• the influence of the atmosphere on the measurements of present and future UHECR and gamma-ray experiments• terrestrial gamma-ray flashes, transient luminous events and general topics in atmospheric electricity• analysis techniques and instruments• public global data sets, models and simulationsWe take advantage of this preface to thank all the participants for the very fruitful discussions that came up during the workshop in a friendly and collaborative atmosphere, among participants of different but complementary fields. This was the main goal of AtmoHEAD 2022.AtmoHEAD 2022 was organized by the Department of Physics “E. Pancini ” of the University of Napoli Federico II and by the Napoli Division of the National Institute of Nuclear Physics (INFN).

Analysis of the Capability of Detection of Extensive Air Showers by Simple Scintillator Detectors

One of the main objectives of the CREDO project is to register cosmic-ray cascades in many distributed detectors in the search for so-called Cosmic-Ray Ensembles (CRE). This requires precise knowledge of the probability of detection of individual Extensive Air Showers (EAS) in a very wide range of energies and an analysis of their correlations. The standard approach based on detailed and extensive simulations is not possible for many such systems; thus, a faster method is developed. Knowing the characteristics of EAS from more general simulations, any required probability is calculated. Such probability depends on particle density at a given point, which is a function of the distance from the centre of the cascade, the energy, mass and the zenith angle of the primary cosmic-ray particle. It is necessary to use proper distribution of the number of secondary particles reaching the ground and their fluctuations. Finally, to calculate the total probability of EAS detection, the primary cosmic-ray spectrum and abundance of various particles in it have to be taken into account. The effective probability can be used to estimate the expected number of EAS events measured by a set of small detectors. In this work, results from several versions of calculations, with different complexity levels, are presented and compared with the first measurement performed with a test detector system. These results confirm that the majority of events observed with this small detector array are caused by cosmic-ray particles with very high energies. Such analysis can be also useful for the design of more effective systems in the future. Slightly larger systems of simple detectors may be used to distinguish cascades initiated by photons from those started from other primary cosmic-ray particles.

Particle Physics with the Pierre Auger Observatory

The Pierre Auger Observatory is the largest extensive air shower detector. Based on a hybrid system, this experiment measures the longitudinal shower development and the particles at the ground. This detection system allows the extraction of the p-air cross-section at energies much higher than the ones accessible by current colliders. It is also possible to test hadronic interaction models using correlations between different air shower observables, like the depth of shower maximum and the muon number at the ground and their fluctuations. Thanks to the low energy extension of the Pierre Auger Observatory, the muon deficit in air shower simulations can be addressed over almost three decades at the highest energies.

Radio interferometry applied to the observation of cosmic-ray induced extensive air showers

We developed a radio interferometric technique for the observation of extensive air showers initiated by cosmic particles. In this proof-of-principle study we show that properties of extensive air showers can be derived with high accuracy in a straightforward manner. When time synchronisation below sim 1 ns between different receivers can be achieved, direction reconstruction resolution of < 0.2^circ and resolution on the depth of shower maximum of <10 g/cm^2 are obtained over the full parameter range studied, with even higher accuracy for inclined incoming directions. In addition, by applying the developed method to dense arrays of radio antennas, the energy threshold for the radio detection of extensive air showers can be significantly lowered. The proposed method can be incorporated in operational and future cosmic particle observatories and with its high accuracy it has the potential to play a crucial role in unravelling the composition of the ultra-high-energy cosmic-particle flux.

Extensive Air Shower Reconstruction using the timing information from the RF-system of the Astroneu array

The Astroneu cosmic ray telescope is a distributed hybrid array consisting of both scintillator counters and RF antenna detectors used for the detection of extensive air showers (EAS). The array is deployed at the Hellenic Open University campus, on the outskirts of the urban area of Patras in Greece. In the present development phase, the Astroneu telescope includes two stations consisting of 3 scintillation detectors modules (SDM) and one RF antenna while a third station includes 3 particle detectors and 4 RF antennas (3SDM-4RF). In each station, the RF-detectors are operating receiving a common trigger upon a 3-fold coincidence between the particle detectors of the station. In this study we present recent results from the 3SDM-4RF autonomous station related to the estimation of the direction of the incoming cosmic air shower using only the timing information from the 4 RF detectors. The directions of the reconstructed showers using the RF timing are in agreement with the corresponding results using the SDMs timing as well as with the simulation predictions. This verifies that the RF signal emitted from EAS originating form Ultra High Energy Cosmic Rays (UHECR), can be detected even in areas with strong electromagnetic background.

First implications of Tibet ASγ data for heavy dark matter

Extensive air shower detectors of gamma rays in the sub-PeV energy region provide a new and relatively unexplored window for dark matter searches. Here we derive some implications of the recently published Tibet AS$_\gamma$ data for decaying dark matter candidates. The available spectral information is already useful in obtaining competitive constraints, surpassing existing limits above 10 PeV mass for hadronic or massive boson final states. This is particularly true if accounting for a benchmark astrophysical background of Galactic cosmic rays in the (0.1-1) PeV range. By relying on the arrival distribution of the photons, we show that significantly better sensitivity can be attained, comparable or better than IceCube also for most leptonic final states. Full data exploitation requires however further information disclosure.

An Ultra-High Time Resolution Cosmic-Ray Detection Mode for the Murchison Widefield Array

The radio-wavelength detection of extensive air showers (EASs) initiated by cosmic-ray interactions in the Earth’s atmosphere is a promising technique for investigating the origin of these particles and the physics of their interactions. The Low-frequency Array (LOFAR) and the Owens Valley Long Wavelength Array (OVRO-LWA) have both demonstrated that the dense cores of low-frequency radio telescope arrays yield detailed information on the radiation ground pattern, which can be used to reconstruct key EAS properties and infer the primary cosmic-ray composition. Here, we demonstrate a new observation mode of the Murchison Widefield Array (MWA), tailored to the observation of the sub-microsecond coherent bursts of radiation produced by EAS. We first show how an aggregate 30.72[Formula: see text]MHz bandwidth ([Formula: see text][Formula: see text]kHz frequency channels) recorded at 0.1[Formula: see text]ms resolution with the MWA’s voltage capture system (VCS) can be synthesized back to the full bandwidth Nyquist resolution of 16.3[Formula: see text]ns. This process, which involves “inverting” two sets of polyphase filterbanks, retains 90.5% of the signal-to-noise of a cosmic-ray signal. We then demonstrate the timing and positional accuracy of this mode by resolving the location of a calibrator pulse to within 5[Formula: see text]m. Finally, preliminary observations show that the rate of nanosecond radio-frequency interference (RFI) events is 0.1[Formula: see text]Hz, much lower than that found at the sites of other radio telescopes that study cosmic rays. We conclude that the identification of cosmic rays at the MWA, and hence with the low-frequency component of the Square Kilometre Array, is feasible with minimal loss of efficiency due to RFI.

Synthesis of radio signals from extensive air showers using previously computed microscopic simulations

The detection of extensive air showers (EAS) through their radio signal is becoming one of the most promising techniques for the study of neutrinos and cosmic rays at the highest energies. For the design, optimization and characterization of radio arrays and their associated reconstruction algorithms, tens of thousands of Monte Carlo simulations are needed. Current available simulation codes can take several days to compute the signals produced by a single shower, making it impossible to produce the required simulations in a reasonable amount of time, in a cost-effective and environmental-conscious way. In this article we present a method to synthesize the expected signals (the full time trace, not just the peak amplitude) at any point around the shower core, given a set of signals simulated in a finite number of antennas strategically located in a pattern that exploits the signature features of the radio wavefront. The method can be applied indistinctly to the electric field or to the antenna response to the electric field, in the three polarization directions, as long as the maximum of the shower is above the horizon. The synthesized signal can be used to evaluate trigger conditions, compute the fluence or reconstruct the shower incoming direction, allowing for the production of a single library of simulations covering the incoming particles phase-space that can be used and re-used for the characterization and optimization of radio arrays and their associated reconstruction methods, for a thousandth part of the otherwise required CPU time.

Scientific and educational aspects of the EEE Project

The Extreme Energy Events (EEE) Project is an experiment aimed at the detection of secondary cosmic ray muons. It consists of a sparse array of about 60 telescopes, based on Multigap Resistive Plate Chambers (MRPCs), mostly distributed throughout the Italian territory, mainly in high schools locations, and at CERN. The telescopes are now operational and taking data since more than ten years with a high duty cycle and detection efficiency. The analysis activity is currently in progress and focused on several items, including the detailed study of the muon ux under dfferent conditions, its connection with atmospheric and solar events, the detection of extensive air showers and the search for long distance correlations between different extensive air showers. In this paper an overall description of the experiment will be given, together with its educational fallout. The operation of the whole array is also discussed by showing the most recent results obtained from the analysis of the collected data.

Reconstruction of Cherenkov radiation signals from extensive air showers of cosmic rays using data of a wide field-of-view telescope

The operation of a wide field-of-view (WFOV) Cherenkov telescope is described. The detection of extensive air showers (EASs) of cosmic rays (CRs) is based upon the coincidence with signals from the Yakutsk array. The data acquisition system of the telescope yields signals connected with EAS development parameters: presumably, shower age and position of shower maximum in the atmosphere. Here, we describe the method of signal processing used to reconstruct Cherenkov radiation signals induced by CR showers. An analysis of signal parameters results in the confirmation of the known correlation of the duration of the Cherenkov radiation signal with the distance to the shower core. The measured core distance dependence is used to set an upper limit to the dimensions of the area along the EAS axis where the Cherenkov radiation intensity is above half-peak amplitude.

The shape of the cosmic ray proton spectrum

Recent observations of cosmic ray protons in the energy range 102–105 GeV have revealed that the spectrum cannot be described by a simple power law. A hardening of the spectrum around an energy of order a few hundred GeV, first observed by the magnetic spectrometers PAMELA and AMS02, has now been confirmed by several calorimeter detectors (ATIC, CREAM, CALET, NUCLEON and DAMPE). These new measurements reach higher energy and indicate that the hardening corresponds to a larger step in spectral index than what was estimated by the magnetic spectrometers. Data at still higher energy (by CREAM, NUCLEON and DAMPE) show that the proton spectrum undergoes a marked softening at E ≈ 104 GeV. Understanding the origin of these unexpected spectral features is a significant challenge for models of the Galactic cosmic rays. An important open question is whether additional features are present in the proton spectrum between the softening and the “Knee”. Extensive Air Shower detectors, using unfolding procedures that require the modeling of cosmic ray showers in the atmosphere, estimated the proton flux below and around the Knee (at E ≃ 3 PeV). These results however have large systematic uncertainties and are in poor agreement with each other. The measurement in the PeV energy range, recently presented by IceTop/IceCube, indicates a proton flux higher than extrapolations of the direct measurements calculated assuming a constant slope, and therefore requires the existence of an additional spectral hardening below the Knee. A clarification of this point is very important for an understanding of the origin of the Galactic cosmic rays, and is also essential for a precise calculation of the spectra of atmospheric neutrinos in the energy range (E ≳ 10 TeV) where they constitute the foreground for the emerging astrophysical ν signal.

Signal Convolution of Wide FOV Cherenkov Telescope

The operation of a wide field-of-view (WFOV) Cherenkov telescope is described. Detection of extensive air showers (EAS) of cosmic rays (CR) is based on the coincidence with signals from the Yakutsk array. The data acquisition system (DAQ) of the telescope yields signals connected with EAS development parameters: shower age and position of shower maximum in the atmosphere. Here we describe the application of digital signal processing for reconstruction of Cherenkov radiation signals induced by air showers.

Horizon-T experiment and detection of Extensive air showers with unusual structure

Horizon-T is an innovative detector system constructed to study temporary structure of Extensive Air Showers (EAS) in the energy range above ~1016 eV coming from a wide range of zenith angles (up to 80°). The system, located at Tien Shan high-altitude Science Station at approximately 3340 meters above the sea level, consists of eight charged particle detection points separated by the distance up to one kilometer. The time resolution of charged particles passage of the detector system is a few ns. This level of resolution allows conducting research of atmospheric development of individual EAS. The total of ~8500 Extensive Air Showers (EAS) with the energy above 1016 eV has been detected during the ~4000 hours of Horizon-T detectors system operations since October 24, 2016 to April 21, 2017. A notable number of events has a spatial and temporary structure that showed the pulses with several maxima (modals or modes) from several detection points of the Horizon-T at the same time as described further in this work. These modes are separated in time from each other starting from tens to thousands of ns. Some are further classified as unusual event with common structure.