Cherenkov Light Lateral Distribution Research Articles

Muon Puzzle in Ultra-High Energy EASs According to Yakutsk Array and Auger Experiment Data

The lateral distribution of particles in extensive air showers from cosmic rays with energy above $10^{17}$ eV registered at the Yakutsk complex array was analyzed. Experimentally measured particle densities were compared to the predictions obtained within frameworks of three ultra-high energy hadron interaction models. The cosmic ray mass composition estimated by the readings of surface-based and underground detectors of the array is consistent with results based on the Cherenkov light lateral distribution data. A comparison was made with the results of direct measurement of the muon component performed at the Pierre Auger Observatory. It is demonstrated that the densities of muon flux measured at Yakutsk array are consistent with results of fluorescent light measurements and disagree with results on muons obtained at the Auger array.

Simulation of Lateral Distribution Function of Cherenkov Light in Extensive Air Showers for Yakutsk Array

The simulation of Cherenkov light Lateral distribution function (LDF) for primary particles like primary protons, Iron nuclei, Oxygen, Nitrogen, Calcium, Neutron and Argon have been performed with CORSIKA code for conditions and configuration of Yakutsk array in the energy range 1014-1016 eV for four zenith angles 0o, 5o, 10o and 15o. The results of this simulation are compared with the measurements of Yakutsk array for the same particles and energyrange

On the estimation of the depth of maximum of extensive air showers using the steepness parameter of the lateral distribution of Cherenkov radiation

Using Monte Carlo simulation of extensive air showers, we showed that the maximum depth of showers, Xmax can be estimated using P=Q(100)∕Q(200), the ratio of Cherenkov photon densities at 100 and 200 meters from the shower core, which is known as the steepness parameter of the lateral distribution of Cherenkov radiation on the ground. A simple quadratic model has been fitted to a set of data from simulated extensive air showers, relating the steepness parameter and the shower maximum depth. Then the model has been tested on another set of simulated showers. The average difference between the actual maximum depth of the simulated showers and the maximum depth obtained from the lateral distribution of Cherenkov light is about 9 g/cm2. In addition, possibility of a more direct estimation of the mass of the initial particle from P has been investigated. An exponential relation between these two quantities has been fitted. Applying the model to another set of showers, we found that the average difference between the estimated and the actual mass of primary particles is less than 0.5 atomic mass unit.

NICHE detector and operations

The Non-Imaging CHErenkov Array (NICHE) is a low energy extension to Telescope Array and TALE using an array of closely spaced (˜ 200m) light collectors covering an area of ˜ 2 square km. It is being deployed in the field of view of TALE and will overlap it in the energy range above 4 PeV. Cosmic ray air showers with energies 1-100 PeV are reconstructed using both the Cherenkov light Lateral Distribution and the Cherenkov time Width Lateral Distribution. These two methods will allow shower energy and X max to be determined. A prototype of the array, called j-NICHE, has been deployed. The performance of detector’s components, current status of the detectors and the observations are presented.

Composition of Cosmic Rays with Energy More than 0.1 EeV by Long-Term Optical Observations of Cherenkov Emission at Yakutsk EAS Array

The paper presents results on longitudinal development of air showers with ultra-high energies and mass composition of cosmic rays 〈ln A〉. The data is obtained from observations of Cherenkov emission at the Yakutsk array in 1974–2014. Cascade curves of individual showers reconstructed by lateral distribution of Cherenkov light and depth of maximum Xmax are analyzed in the energy region 1016–6 × 1019 eV. Composition of cosmic rays is determined by interpolation of hadronic interaction QGSJETII-04 model.

Studying the Possibility of Separation of Primary Nuclei Groups in the Energy Interval 300 TeV – 10 PeV in the TAIGA-HiSCORE Experiment

We proposed a method of discrimination between light (p+He) and heavy (C+Fe) groups of primary nuclei. It’s based on parametric analysis of lateral distribution of Cherenkov light in the atmosphere with approximation by the ‘knee-like’ fitting function, proposed and studied earlier. Two parameters most sensitive to the depth of shower maximum were revealed and used for analysis of the bulk of experimental data obtained in the TAIGA-HiSCORE experiment in the energy range 300–3000 TeV for various incident angles of particles. It is shown that the method allows estimating the contribution of light and heavy groups of primary nuclei. In the interval 300–3000 TeV we do not see a rapid decrease of the light component flux, as it was seen in the ARGO-YBJ experiment. This result will be refined after a more detailed analysis.

Spatial and temporal structure of EAS reflected Cherenkov light signal

A compact device lifted over the ground surface might be used to observe optical radiation of extensive air showers (EAS). Here we consider spatial and temporal characteristics of Vavilov-Cherenkov radiation (“Cherenkov light”) reflected from the snow surface of Lake Baikal, as registered by the SPHERE-2 detector. We perform detailed full direct Monte Carlo simulations of EAS development and present a dedicated highly modular code intended for detector response simulations. Detector response properties are illustrated by example of several model EAS events. The instrumental acceptance of the SPHERE-2 detector was calculated for a range of observation conditions. We introduce the concept of “composite model quantities”, calculated for detector responses averaged over photoelectron count fluctuations, but retaining EAS development fluctuations. The distortions of EAS Cherenkov light lateral distribution function (LDF) introduced by the SPHERE-2 telescope are understood by comparing composite model LDF with the corresponding function as would be recorded by an ideal detector situated at the ground surface. We show that the uncertainty of snow optical properties does not change our conclusions, and, moreover, that the expected performance of the SPHERE experiment in the task of cosmic ray mass composition study in the energy region ∼ 10 PeV is comparable with other contemporary experiments. Finally, we compare the reflected Cherenkov light method with other experimental techniques and briefly discuss its prospects.

Background rejection method for tens of TeV gamma-ray astronomy applicable to wide angle timing arrays

A ‘knee-like’ approximation of Cherenkov light Lateral Distribution Functions, which we developed earlier, now is used for the actual tasks of background rejection methods for high energy (tens and hundreds of TeV) gamma-ray astronomy. In this work we implement this technique to the HiSCORE wide angle timing array consisting of Cherenkov light detectors with spacing of 100 m covering 0.2 km2 presently and up to 5 km2 in future. However, it can be applied to other similar arrays. We also show that the application of a multivariable approach (where 3 parameters of the knee-like approximation are used) allows us to reach a high level of background rejection, but it strongly depends on the number of hit detectors.

Demonstrating of Cosmic Ray Characteristics by Estimating the Cherenkov Light Lateral Distribution Function for Yakutsk Array as a Function of the Zenith Angle

Cherenkov light lateral distribution function (CLLDF) in Extensive Air Showers (EAS) for different primary particles (e-, n , p, F, K and Fe) was simulated using CORSIKA code for conditions and configurations of Yakutsk EAS array with the fixed primary energy 3 PeV around the knee region at different zenith angles. Basing on the results of CLLDF numerical simulation, sets of approximated functions are reconstructed for different primary particles as a function of the zenith angle. A comparison of the parametrized CLLDF with that simulated with Yakutsk EAS array is verified.The parameterized CLLDF also is compared with that measured on the Yakutsk EAS array.

Demonstrating of Cosmic Ray Characteristics by Estimating the Cherenkov Light Lateral Distribution Function for Yakutsk Array as a Function of the Zenith Angle

Cherenkov light lateral distribution function (CLLDF) in Extensive Air Showers (EAS) for different primary particles (e-, n , p, F, K and Fe) was simulated using CORSIKA code for conditions and configurations of Yakutsk EAS array with the fixed primary energy 3 PeV around the knee region at different zenith angles. Basing on the results of CLLDF numerical simulation, sets of approximated functions are reconstructed for different primary particles as a function of the zenith angle. A comparison of the parametrized CLLDF with that simulated with Yakutsk EAS array is verified.The parameterized CLLDF also is compared with that measured on the Yakutsk EAS array.

Parameterization of Cherenkov Light Lateral Distribution Function as a Function of the Zenith Angle around the Knee Region

Cherenkov light lateral distribution function (CLLDF) simulation was fullfiled using CORSIKA code for configurations of Tunka EAS array for different zenith angles. The parameterization of the CLLDF was carried out as a function of the destance from tehe shower core in extensive air showers (EAS) and zenith angle on the basis of the CORSIKA simulation for primary proton around the knee region with the energy 3.1015 eV at different zenith angles. The parametrized CLLDF is verified in comparison with the simulation that performed using CORSIKA code for two zenith angles.

Parameterization of Cherenkov Light Lateral Distribution Function as a Function of the Zenith Angle around the Knee Region

Cherenkov light lateral distribution function (CLLDF) simulation was fullfiled using CORSIKA code for configurations of Tunka EAS array for different zenith angles. The parameterization of the CLLDF was carried out as a function of the destance from tehe shower core in extensive air showers (EAS) and zenith angle on the basis of the CORSIKA simulation for primary proton around the knee region with the energy 3.1015 eV at different zenith angles. The parametrized CLLDF is verified in comparison with the simulation that performed using CORSIKA code for two zenith angles.

Investigating the Cherenkov light lateral distribution function for primary proton and iron nuclei in extensive air showers

The lateral distribution function (LDF) of Cherenkov radiation in extensive air showers (EAS) was simulated by CORSIKA program for the conditions of Yakutsk Cherenkov array at the high energy range (1013–1016) eV for two primary particles (p and Fe) for different zenith angles. By depending on Breit-Wigner function for analyzing of Cherenkov light LDF, a parameterization of Cherenkov light LDF was reconstructed by depending on CORSIKA simulation as a function of primary energy. The comparison between the estimated Cherenkov light LDF with the LDF that measured on the Yakutsk EAS array gives the ability of particle identification that initiated the shower and determination of particle’s energy around the knee region. The extrapolation of approximated Cherenkov light LDF for energies 20 and 30 PeV was obtained for primary particles (p and Fe).

Estimating of Cherenkov Radiation in Extensive Air Showers Using CORSIKA Code for Tunka133 EAS Cherenkov Array

The simulation of Cherenkov light Lateral distribution function (LDF) in Extensive Air Showers (EAS) initiated primary particles such as primary calcium, argon, proton iron nuclei, neutron and nitrogen have been performed using CORSIKA program for conditions and configurations of Tunka133 EAS Cherenkov array. The simulation was fulfilled at the high energy range 1014-1016eV for four different zenith angles 0o, 10o, 15oand 30o. The results of the simulated Cherenkov light LDF are compared with the measurements of Tunka133 EAS array for the same particles and energy range mentioned above. This comparison may give the good ability to reconstruct the energy spectrum and mass composition of the primary cosmic ray particles in EAS. The main feature of the given approach consists of the possibility to make a library of Cherenkov light LDF samples which could be utilized for analysis of real events which can be detected with different EAS arrays and reconstruction of the primary cosmic rays energy spectrum and mass composition of EAS particles.

Study of Cherenkov light lateral distribution function around the knee region in extensive air showers

The Cherenkov light lateral distribution function (LDF) was simulated with the CORSIKAcode in the energy range (1013 - 1016) eV. This simulation was performed for conditions and configurations of the Tunka EAS Cherenkov array for the two primary particles (p and Fe). Basing on the simulated results, many approximated functions are structured for two primary particles and different zenith angles. This allowed us to reconstruct the EAS events, which is, to determine the type and energy of the primary particles that produced showers from signal amplitudes of Cherenkov radiation measured by the Tunka Cherenkov array experiment. Comparison of the calculated LDF of Cherenkov radiation with that measured at the Tunka EAS array shows the ability to identify the primary particle that initiated the EAS cascades by determining its primary energy around the knee region of the cosmic ray spectrum.

Extension of Cherenkov Light LDF Parametrization for Tunka and Yakutsk EAS Arrays

The Cherenkov light Lateral Distribution Function (LDF) from particles initiated Extensive Air Showers (EAS) with ultrahigh energies (E > 1016 eV) was simulated using CORSIKA program for configuration of Tunka and Yakutsk EAS arrays for different primary particles (p, Fe and O2) and different zenith angles. By depending on the Breit–Wigner function, a parametrization of the Cherenkov light LDF was reconstructed on the basis of this simulation as a function of the primary energy. The comparison of the approximated Cherenkov light LDF with that measured on Tunka and Yakutsk EAS arrays gives the possibility of identification of energy spectrum and mass composition of particles initiating EAS about the knee region of the cosmic ray spectrum. The extrapolation of approximated Cherenkov light LDF for energies 20, 30 and 50 PeV was obtained for different primary particles and different zenith angles.

Extension of Cherenkov Light LDF Approximation for Yakutsk EAS Array

The simulation of the Cherenkov light lateral distribution function (LDF) in extensive air showers (EAS) was performed using CORSIKA code for configuration of Yakutsk EAS array at high energy range for different primary particles (p, Fe, and O2) and different zenith angles. Depending on Breit-Wigner function a parameterization of Cherenkov light LDF was reconstructed on the basis of this simulation as a function of primary energy. A comparison of the calculated Cherenkov light LDF with that measured on the Yakutsk EAS array gives the possibility of identification of the particle initiating the shower and determination of its energy in the knee region of the cosmic ray spectrum. The extrapolation of approximated Cherenkov light LDF for high energies was obtained for primary proton and iron nuclei.

Analysis of Lateral Distribution of Atmospheric Cherenkov Light at High Mountain Altitude Towards Event Reconstruction

Air shower simulations with CORSIKA6.990 code using FLUKA 2011 and QGSJET II hadron generators are performed. The simulations are carried out at high mountain observation level, namely, Chacaltaya cosmic ray station. The lateral distribution of atmospheric Cherenkov light produced by various primary particles, namely, proton, helium, oxygen, and iron nuclei, is obtained over wide energy range, between 1011 eV and 1017 eV. The lateral distribution is obtained, integrating over time and angle Cherenkov photons till 800 m from the shower axis. The shapes of the obtained distributions are compared and parameterized. Three different approximations of lateral distribution of Cherenkov light are compared. On the basis of inverse problem solution an event analysis, towards mass composition and energy reconstruction of the primary particle, is carried out. The applications and scientific potential for HECRE experiment proposal are discussed.

Influence of the scattered Cherenkov light on the width of shower images as measured in the EAS fluorescence experiments

We calculate the lateral distribution of Cherenkov light at different levels of shower development. The calculations use the universal characteristics of large showers. We derive that the angular and lateral distributions of Cherenkov photons emitted by a shower path element depend only on the shower age and height in the atmosphere of this element. The width of a shower image in the Cherenkov scattered light also depends, however, on the zenith angle and X max . We also show that below shower maximum it is considerably wider than the width in the fluorescence light.

PRIMARY ENERGY MEASUREMENT WITH EAS CHERENKOV LIGHT: EXPERIMENT QUEST AND CORSIKA SIMULATION

A new primary mass independent method of energy measurement has been developed by exploiting: a) the joint analysis of the shower size, obtained by EAS-TOP, and of the EAS atmospheric Cherenkov light lateral distribution, obtained by the QUEST array, and b) simulations based on the CORSIKA/QGSJET code. The method is based on the correlation between the size/energy ratio and the steepness of Cherenkov light lateral distribution and has been compared with a "classical" one based on the Cherenkov light flux at a fixed distance (175 m) from the EAS core. An absolute energy calibration of the EAS atmospheric Cherenkov light flux has been obtained.