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. 1. Introduction Study of the energy spectrum and mass composition of primary cosmic rays (PCRs) in the energy range 1013–1017？eV is of a special interest in connection with observed index change of PCR spectrum close to ？PeV which is called the “knee” region [1, 2]. The Cherenkov light emitted in the atmosphere by relativistic electrons of cosmic rays (CRs) in EAS carries important information about the shower development and PCR particles. The Cherenkov light LDF depends on energy and type of the primary particle, observation level, height of the first interaction, and direction of shower axis [3]. The Monte Carlo method is one of the necessary tools of numerical simulation for investigation of EAS characteristics and experimental data processing and analysis (determination of the primary particle energy type and direction of shower axis from the characteristics of Cherenkov radiation of secondary charged particles). Agnetta et al. [4] have discussed the simulation and the experimental setup with detailed information on the detection of Cherenkov light method in EAS. On the other side, Akchurin et al. [5] have presented detailed measurements of high-energy electromagnetic and hadronic shower profiles. The Cherenkov light LDF generated in the shower development process was measured for electrons in the energy range 8–200？GeV. The Cherenkov light profiles are discussed and compared with results of Monte Carlo simulations. Berezhnev et al. [6] have installed the Cherenkov light EAS array (Tunka-133). This array permits a detailed study of cosmic ray energy spectrum and mass composition in the energy range 1016–1018？eV with a uniform method. The analysis of LDF and time structure of EAS Cherenkov light allowed estimating the depth of the EAS maximum . In the
References
[1]
G. B. Khristiansen, Y. A. Fomin, N. N. Kalmykov et al., “The primary cosmic ray mass composition around the knee of the energy spectrum,” Nuclear Physics B: Proceedings Supplements, vol. 39, no. 1, pp. 235–241, 1995.
[2]
M. Amenomori, Z. Cao, B. Z. Dai et al., “The cosmic-ray energy spectrum between 1014.5 and 1016.3？eV covering the knee region,” The Astrophysical Journa, vol. 461, pp. 453–460, 2008.
[3]
A. A. Al-Rubaiee, O. A. Gress, K. S. Lokhtin, Y. V. Parfenov, and S. I. Sinegovskii, “Modeling and parameterization of the spatial distribution of ？erenkov light from extensive air showers,” Russian Physics Journal, vol. 48, no. 10, pp. 1004–1011, 2005.
[4]
G. Agnetta, P. Assis, B. Biondo, et al., “Extensive air showers and diffused Cherenkov light detection: The ULTRA experiment,” Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 570, pp. 22–35, 2007.
[5]
N. Akchurin, K. Carrell, J. Hauptman et al., “Comparison of high-energy electromagnetic shower profiles measured with scintillation and Cherenkov light,” Nuclear Instruments and Methods in Physics Research A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 548, no. 3, pp. 336–354, 2005.
[6]
S. F. Berezhnev, D. Besson, N. M. Budnev et al., “The Tunka-133 EAS Cherenkov light array: status of 2011,” Nuclear Instruments and Methods in Physics Research A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 692, pp. 98–105, 2012.
[7]
S. Knurenko, V. Kolosov, Z. Petrov, I. Sleptsov, and S. Starostin, in Proceedings of the 28th International Cosmic Ray Conference (ICRC '03), pp. 177–179, Tsukuba, Japan, 2003.
[8]
A. A. Ivanov, S. P. Knurenko, and I. Y. Sleptsov, “Measuring extensive air showers with Cherenkov light detectors of the Yakutsk array: the energy spectrum of cosmic rays,” New Journal of Physics, vol. 11, Article ID 065008, 30 pages, 2009.
[9]
D. Heck and T. Peirog, Extensive Air Shower Simulations at the Highest Energies—A User's Guide, Institut fur Kernphysik, Heidelberg, Germany, 2013.
[10]
J. Knapp, D. Heck, S. J. Sciutto, M. T. Dova, and M. Risse, “Extensive air shower simulations at the highest energies,” Astroparticle Physics, vol. 19, no. 1, pp. 77–99, 2003.
[11]
S. Ostapchenko, “QGSJET-II: towards reliable description of very high energy hadronic interactions,” Nuclear Physics B: Proceedings Supplements, vol. 151, pp. 143–146, 2006.
[12]
D. Heck and R. Engel, in Proceedings of the 28th International Cosmic Ray Conference, pp. 279–282, Tsukuba, Japan, 2003.
[13]
S. C. Mavrodiev, A. L. Mishev, and J. N. Stamenov, “A method for energy estimation and mass composition determination of primary cosmic rays at the Chacaltaya observation level based on the atmospheric Cherenkov light technique,” Nuclear Instruments and Methods in Physics Research A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 530, no. 3, pp. 359–366, 2004.
[14]
A. Mishev, “Analysis of lateral distribution of atmospheric cherenkov light at high mountain altitude towards event reconstruction,” ISRN High Energy Physics, vol. 2012, Article ID 906358, 12 pages, 2012.
[15]
N. Aliev, T. Alimov, M. Kakhkharov, et al., in Proceedings of the 18th International Cosmic Ray Conference (ICRC '83), vol. 2, pp. 383–386, Bangalore, India, 1983.
[16]
A. Mishev, I. Angelov, E. Duverger, R. Gschwind, L. Makovicka, and J. Stamenov, “Experimental study and Monte Carlo modeling of the Cherenkov effect,” Nuclear Instruments and Methods in Physics Research A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 474, no. 2, pp. 101–107, 2001.
