Development Of Extensive Air Showers Research Articles

Lateral distribution cosmic ray muon coincidences up to 36 m

Primary cosmic ray particles comprise about 85 % protons, 12 % helium, 3 % iron, and heavier elements. These particles interact with the Earth's atmosphere, generating the Extensive Air Showers (EAS). Among the particles produced are pions and kaons, which decay into cosmic ray muons. In this research, the lateral distribution of cosmic ray muons was measured using two-fold coincidences. Four NaI (Tl) detectors and the associated electronics were used in the measurements of cosmic ray muons. The detectors were positioned from 0 to 36 m at regular intervals. The muon count rate was observed to decrease as the distance between the detectors increased. The measurements were fitted to the Nishimura–Kamata–Greisen (NKG) function to analyze the lateral distribution. Monte Carlo (MC) simulations of EAS were performed using the Cosmic Ray Simulations for the KAscade Grande (CORSIKA) program. The simulations made use of EPOS and GHEISHA models for high and lower energies respectively.•The measurements for the two-fold coincidence are consistent with the NKG function.•The simulated and measured data were found to be in agreement.•The knowledge gained from the lateral distribution of cosmic ray muons is essential for the understanding of the development of extensive air showers.

Ultra-peripheral collisions of charged hadrons in extensive air showers

We discuss the electromagnetic collisions of high energy protons, pions and kaons with atmospheric nuclei. In particular, we use the equivalent photon approximation to estimate (i) the diffractive collisions where the projectile scatters inelastically off a nucleus, and (ii) the usual radiative processes (bremsstrahlung, pair production and photonuclear interactions) of these charged hadrons in the air. We then include the processes in the simulator AIRES and study how they affect the longitudinal development of extensive air showers. For 109-11 GeV proton primaries we find that they introduce a very small reduction (below 1%) in the average value of both X max and ΔX max. At a given shower age (relative slant depth from X max), these electromagnetic processes slightly increase the number of charged particles at the shower maximum and reduce the number of muons when it is old, decreasing by 1% the muon-to-(γ + e) near the ground level.

The Influence of the Strong Atmospheric Electric Fields on the Extensive Air Shower Development

The Influence of the Strong Atmospheric Electric Fields on the Extensive Air Shower Development

Searches for Lorentz Invariance Violation at the Pierre Auger Observatory

Lorentz Invariance (LI) requires the space-time structure to be the same for all observers, but various quantum gravity theories suggest that it may be violated when approaching the Planck scale. Even a small violation of LI could easily affect the Ultra-High-Energy Cosmic Ray (UHECRs) propagation on a cosmological scale. Moreover, at the extreme energies, like those available in the collisions of UHECRs in the atmosphere, one should also expect a change in the development of Extensive Air-Showers (EAS). In this contribution, Lorentz Invariance Violation (LIV) has been introduced as a perturbation term in the single particle dispersion relation considering a phenomenological approach. As a result, the kinematics of the interactions in both the extragalactic propagation and in the shower development in the atmosphere is affected. The comparison between the model predictions and the data measured by the Pierre Auger Observatory are considered to constrain the LIV scenarios. The impact of LIV has been tested considering the measured energy spectrum and the composition and the resulting upper limits on the photon flux. Finally, the effects on the shower cascade in the atmosphere are studied considering the muon content distribution.

Simulating and Modeling the Extensive Air Showers Development through the Estimating the Energy of some Created Particles

Using the AIRES code and three hadronic interaction models, a simulation study of the energy of created particles due to the development of an extensive air shower was carried out (EPOS-LHC, QGSJET-II-04, and Sibyll2.3c). The main focus is put on the energy of the create particles as a function of depth for (12C,56Fe, p, and 28Si) primary particles with high primary energies (1017,1018,1019, and 1020) eV with two zenith angles 0° and 30°. The New parameters were obtained by fitting the energy of created particles curves using Gaussian and linear functions for created particles, initiated by primary particles at the energy 1020 eV. Good agreement was obtained by comparing the present results with results simulated by CORSIKA simulation for primary proton at the energy 1019 eV

Probing hadronic interactions with measurements from the Pierre Auger Observatory

The Pierre Auger Observatory is the largest facility in the world to study ultra-high-energy cosmic rays. It has a hybrid detection technique that combines the observation of the longitudinal development of extensive air showers and the measurement of their particles at the ground. This capability has opened the possibility to probe hadronic interactions taking place at energies well beyond those accessible by human-made accelerators. In this report, we present a selection of the latest results on hadronic interactions with measurements from the Pierre Auger Observatory. These data span over three decades in energy, showing the tension between data from the muon component of air showers and predictions based on the most updated hadronic interaction models.

Symmetries in the Superposition Model of Extensive Air Shower Development

According to the superposition principle, an extensive air shower initiated by a nucleus with energy E and mass number A can be approximated as the superposition of A proton-initiated showers each with energy E/A. The superposition principle for interactions of atomic nuclei proposes to describe nucleus-initiated extensive air showers using simulations performed for proton showers. Single detectors and systems working in tight coincidence mainly register events initiated by particles with very low energies, which are affected by major statistical fluctuations, such as those used in high schools for education and outreach purposes. Verifying whether the superposition principle is still a good approximation in the low-energy region is important for the validity of the interpretation of such measurements. We present results of the comparison of results of the superposition model with detailed simulations of showers with the CORSIKA program from the energy of 10 GeV. While the energy dependence of the mean shower parameters satisfies the superposition principle, the higher moments do not. A modification of the superposition model based on the wounded nucleon model, reducing these discrepancies, is proposed. The semi-analytical description of showers in the modified superposition model can give the density spectrum of cosmic ray particles, which is consistent with the measurements. In this paper, we present results both consistent with the superposition model and indicating the need for its modification. This modification is proposed and tested.

Testing the superposition model in small CORSIKA shower simulations

The idea of superposition in the high-energy interactions of cosmic ray nuclei and the development of extensive air showers initiated by them has been known for more than half a century. It has been thoroughly and successfully tested in a number of simulations for primary energies around 1015 and above. In this work, we will investigate its applicability to lower energies. At the lowest energies, when the shower contains on average about one charged particle (or even less), deviations from the superposition model can be seen in the simulation results. Fluctuations of higher moments of the main shower parameters are systematically broader than expected. Further studies to confirm superposition in particular in the shower longitudinal profile are in progress. A correct description of the longitudinal development of the small shower, a precise description of its fluctuations on the observational level with a correct implementation of the superposition principle will enable to construct a simple and fast phenomenological algorithm generating small showers indispensable for the interpretation of measurements made using a small local shower array and determination of the flux of single, incoherent, secondary cosmic ray particles.

Muon Tomography sites for Colombian volcanoes

By using a very detailed simulation scheme, we have calculated the cosmic ray background flux at 13 active Colombian volcanoes and developed a methodology to identify the most convenient places for a muon telescope to study their inner structure. Our simulation scheme considers three critical factors with different spatial and time scales: the geo-magnetic effects, the development of extensive air showers in the atmosphere, and the detector response at ground level. The muon energy dissipation along the path crossing the geological structure is modeled considering the losses due to ionization, and also contributions from radiative Bremßtrahlung, nuclear interactions, and pair production. By examining each particular volcano topography and assuming reasonable statistics for different instrument acceptances, we obtained the muon flux crossing each structure and estimated the exposure time for our hybrid muon telescope at several points around each geological edifice. After a detailed study from the topography, we have identified the best volcano to be studied, spotted the best points to place a muon telescope and estimated its time exposures for a significant statistics of muon flux. We have devised a mix of technical and logistic rules –the “rule of thumb” criteria– and found that only Cerro Machín, located at the Cordillera Central (4°29'N 75°22'W), can be feasibly studied today through muography. Cerro Negro and Chiles could be good candidates shortly.

Muons in Extensive Air Showers with Energy above 1017 eV According to the Long Standing Studies at the Yakutsk Array

lateral distribution of muons was studied in extensive air showers initiated by cosmic rays with energy above 1017 eV. The study is based on the experimental data of underground scintillation detectors with 1-GeV energy threshold collected during the continuous observational period lasting from 1986 to 2017. Experimentally measured values of muon density are compared to results of simulations performed for primary protons and iron nuclei within the framework of four ultra-high energy hadronic interaction models. The density of particles with 1-GeV threshold obtained in simulations was then converted to the signal of ground-shielded scintillation detectors of the array. Studying the features of the resulting muon lateral distribution has allowed us to reconstruct parameters of longitudinal development of extensive air showers.

Fluctuations of the Maximum Depth of EASes with Energies Greater than 1017 eV, According to Measurements of Radio Emission at Frequencies of 30–35 MHz

Results on the longitudinal development of extensive air showers (EAS) of ultrahigh energies are obtained from observations of radio emission at the Yakutsk array for the periods from 1986 to 1989 and from 2009 to 2014. The maximum depth of individual showers is determined and a statistical analysis of Xmax is performed to estimate the fluctuations in the development of EAS σ(Xmax) in the energy region of 1017–1018 eV. It is shown that σ(Xmax) is 50–60 g cm2 in the energy range of 1017–1018 eV, which does not contradict the mixed composition of cosmic rays (protons and helium nuclei). Data on the dependence of Xmax on energy also indicate this.

Maximum Depth of Development of EASes with Energies above 1016 eV, Measured in Individual Events by Cherenkov Tracking Detectors

The Cherenkov radiation of extensive air showers (EASes) is studied using a system of optical tracking detectors based on a camera obscura as part of the Yakutsk EAS complex. These detectors allow photons to be counted from a certain height in the atmosphere and thus reconstruction of longitudinal development of a shower. Good coincidence is observed between EAS cascade curve parameter Xmax measured in this way and by modeling. Preliminary results on the cosmic ray mass composition are obtained for energies above 1016 eV.

Mass composition of cosmic rays above 0.1 EeV by the Yakutsk array data

The paper presents the results of the longitudinal development of extensive air showers (Xmax) of ultra-high energies and mass composition of cosmic rays. The measurements of Xmax are based on data from observations of the Cherenkov radiation at the Yakutsk array for the period 1974–2014. The cascade curves of individual showers and the depth of maximum Xmax were reconstructed over the energy range 1016–5.7 · 1019 eV. It is shown that the displacement rate of the parameter dXmax/dE in the atmosphere is nonlinear and depends on the energy. Such a feature indicates a change in mass composition, which is confirmed by fluctuations of Xmax in this energy region. The composition of cosmic rays was determined by interpolation using the QGSJetII-04 model.

Zenith angle dependence of the cosmic ray rate as measured with imaging air-Cherenkov telescopes

The rate of extensive air-showers observed with imaging air-Cherenkov telescopes is zenith angle dependent. This effect originates from the increasing geometrical distance of the observed shower to the telescope with increasing zenith distance. This paper investigates how this alters the observed image and how this affects the trigger rate as a function of zenith angle. The discussed effects include the change of Cherenkov light yield, of absorption in the atmosphere, of photon density at the aperture and of the image size at the focal plane of the telescope. Based on a simple model for the atmosphere and well-known first principles on the development of extensive air-showers, the zenith angle dependence is expressed analytically. The assumption that most light is emitted from the shower core and mathematical approximations allow to derive an analytical expression describing the zenith angle dependence well with only three free parameters which are directly linked with the underlying physics. This suggests further investigations about how these fit parameters are linked to the properties of the atmosphere and the instrument. Using data published by the First G-APD Cherenkov Telescope, a good match of the fit functions with the data is obtained. For the trigger rate of cosmic rays, the obtained parameters are consistent with the naive expectation.

Testing of almost all the hadronic interaction models by comparing calculated muon energy spectrum with data

Uncertainties of the model energy spectra of the most energetic secondary charged mesons are discussed. Computer simulations of the partial energy spectra of the atmospheric vertical muons induced by primary cosmic particles with various fixed energies in terms of hadronic interactions models had been carried out with the help of the CORSIKA package. These partial spectra have been convolved with the contemporary spectra of the primary cosmic particles in the energy range 0.1-10 000 TeV. Results of simulations are compared with the contemporary data of the atmospheric vertical muon flux. Comparison shows that all models underestimate the production of secondary charged π±-mesons (and K±-mesons) by a factor of ~ 1.4 ÷ 2 at the highest energies. This underestimation induces a more rapid development of extensive air showers in the atmosphere and results in uncertainties in estimates of energy and composition of the primary cosmic particles.

Composition of Cosmic Rays with E0 ⩾ 1017 eV Based on Data from the Ground Scintillation Detectors of the Yakutsk EAS Array

The lateral distribution of cascade particles in extensive air showers from cosmic rays with energy E0 ⩾ 1017 eV has been studied at the Yakutsk array by the ground scintillation detectors over the period of continuous observations 1977–2017. The experimental data are compared with those computed with various models for the development of extensive air showers from the CORSIKA software package. The best agreement between the theory and experiment is observed for the QGSjet-01-d model. In the energy range (1−20)× 1017 eV there is a change in the cosmic-raymass composition from 〈lnA〉 ≈ 2.5 to the proton one.

Space fluorescence detection of ultra-high energy cosmic rays based on CORSIKA simulation

Abstract Using the Earth’s atmosphere as a calorimeter, the air fluorescence light observation technique is commonly used in Ultra-High Energy Cosmic Ray (UHECR) experiments. The aim is to reconstruct the shower cascade curve and to estimate the primary particle energy and its arrival direction. With the help of the CORSIKA air shower simulation program, the development of extensive air showers (EAS), initiated by primary particles entering the Earth’s atmosphere with energies up to 100 EeV, is performed with different combinations of high and low hadronic interaction models. The sensitivity of longitudinal distribution of particles and energy deposited into the air are studied for different simulation parameters. For a space fluorescence telescope aboard the International Space Station (ISS), the number of fluorescence photons and the profile of their arrival times to the detector pupil are calculated for typical extreme energy events.

Estimation of mass composition of high energy cosmic rays via modeling a relation between lateral distribution parameters and shower age

Lateral distribution function of extensive air showers of energetic cosmic rays, indicate how secondary particles spread over a surface detectors. There are many different universal formulas between lateral distribution parameters and shower age parameter which can be used to infer about maximum development of extensive air shower (which is a key parameter to estimate the mass composition of primary cosmic rays). At present work, an estimated percent of mass composition of ultra-high energy cosmic rays is investigated by comparison between Ivanov et al. modeling of simulated data, which has been done by CoRSiKa, and Yakutsk experimental data.

The detector on the basis of drift chambers for inclined muon bundle investigations

The results of experiments of the last decades have shown that with the increase of energy of primary cosmic rays a clear excess of muon groups in comparison with the existing models of extensive air shower development (even assuming pure iron composition of PCR) appears. The problem is called 'muon puzzle' and it can be explained either by cosmo- or nuclear-physical reasons. One of the experiments in which the excess of muon groups was registered is a NEVOD-DECOR. The new large-scale coordinate-tracking detector of 254 m2 area based on drift chambers will increase the coverage of the side aperture of the Cherenkov water detector (CWD) NEVOD and significantly improve the resolution of close tracks. Multi-wire drift chambers TREK developed in IHEP for experiments at the neutrino channel of U-70 accelerator have large effective area (1.85 m2), a good coordinate and angular resolution with a small number of measuring channels. The first part of the detector named Coordinate-Tracking Unit based on the Drift Chambers (CTUDC) representing two coordinate planes of 8 drift chambers in each has been developed and mounted on the opposite sides of the CWD. It has the same principle of joint operation with NEVOD-DECOR triggering system so the main features of the TREK detector will be examined. Results of an examination of drift chambers at muon hodoscope URAGAN, a calibration of the CTUDC with DECOR and the first results of its joint operation with NEVOD triggering system are presented.

Studying depth of shower maximum using variable interaction length

Due to the high energy interactions of cosmic ray particles, progressive showers of secondary particles initiate in the atmosphere. Several models are suggested to describe the longitudinal development of extensive air showers, for example the Heitler model. The Heitler model also is written for hadronic showers. Anyhow, the predicted values of $X_{max}$ may differ significantly with the values from detailed simulations by up to about $100~(\mbox{g}/\mbox{cm}^{2})$ . In the present work, the mean depth of shower maximum is calculated using a variable interaction length. New equations for $X_{max} $ in the electromagnetic and hadronic showers have been obtained.