GROUND-BASED EXTENSIVE AIR SHOWER ARRAY


SHOWER
ARRAY LAYOUT

    Detector stations of the Extensive Air Shower array are deployed on the 5 concentric circles of radii R = 20, 28, 50, 70 and 100 m, and each station contains 3 square plastic scintillation detectors with the dimensions (1×1×0.05) m³ . Each of the central 9 stations contains an additional (fourth) small scintillator with dimensions (0.3×0.3×0.05) m³ for high particle density (ρch≫10² particles/m²) measurements.
   In figure (right), the black squares symbols represent detector stations. Hollow circle symbols represent single detectors.
    Detected shower size region is 105≲Nch≲108 in the zenith angular range 0≤θ≲60°. The corresponding studied primary nuclei energy range is 1≲E₀≲500 PeV,    .
    The results of EAS study are presented below.

      Layout of detector stations and single detectors.

 

CURRENT RESEARCH (2015)

arXiv:1405.5472, Physical Review D 89, 123003 (2014)

     SHOWER SIZE SPECTRA


GAMMA and Standardized World Data




     ALL-PARTICLE PRIMARY ENERGY SPECTRUM




     ENERGY SPECTRA for H, He, O, Fe PRIMARY NUCLEI

RESULTS FOR 2007-2009

  • Romen M. Martirosov, Samvel V. Ter-Antonyan, Anatoly D. Erlykin, Alexandr P. Garyaka, Natalya Nikolskaya, Yves Gallant and Lawrence W. Jones, "Galactic diffuse gamma-ray flux at the energy about 175 TeV", arXiv:0905.3593, Proceedings of 31-th International Cosmic Ray Conference, Lodz, Poland (2009).

    UPPER LIMIT OF GAMMA RAY FLUX

     

  • A.P. Garyaka, R.M. Martirosov, S.V. Ter-Antonyan, A.D. Erlykin, N. Nikolskaya, Y.A. Gallant, L. Jones, and J. Procureur: "All-particle primary energy spectrum in the 3-200 PeV energy range" arXiv:0808.1421 or Journal of Physics G: Nuclear and Particle Physics, 35 (2008) 115201. http://stacks.iop.org/0954-3899/35/115201.


     

  • R.M. Martirosov , A.P. Garyaka, S.V. Ter-Antonyan, A.D. Erlykin, N.M. Nikolskaya, Y.A. Gallant, L.W. Jones, and J. Procureur: "Does the GAMMA experiment detect the polar cap component at energies 70-80 PeV?" Nuclear Physics B 196 (2009) 173   .


     

  • A.P. Garyaka, R.M. Martirosov, S.V. Ter-Antonyan, N. Nikolskaya, Y.A. Gallant, L. Jones, J. Procureur. "Rigidity-dependent cosmic ray energy spectra in the knee region obtained with the GAMMA experiment". Astroparticle Physics, Volume 28, issue 2 (2007) p. 169, arXiv:0704.3200.


     

  • S.V. Ter-Antonyan, "Mutually compensative pseudo solutions of primary energy spectra in the knee region". Astroparticle Physics 28, issue 3 (2007) p. 321, arXiv:0706.4087.
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PRELIMINARY DATA (2005)

  • S.V. Ter-Antonyan, R.M. Martirosov, A.P. Garyaka, V. Eganov, N. Nikolskaya, T. Episkoposyan, J. Procureur, Y. Gallant, L. Jones: "Primary Energy Spectra and Elemental Composition. GAMMA Experiment". astro-ph/0506588 (2005).


     

  • S.V. Ter-Antonyan, Y.A. Gallant, A.P. Garyaka, L.W. Jones, R.M.Martirosov, N.M. Nikolskaya, J. Procureur: "All-particle primary energy spectrum in the knee region". Proceedings 29th ICRC, Pune, India, (2005)  .

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    ♦

    2004-2005

    Event-by-event primary energy evaluations regardless of primary nucleus.

    Unique results of GAMMA Experiment: 15% accuracy of primary energy determination has been attained using 6-parametric (a₁ ,...,a₆ ) fits:

    LnE₀ =a₁ LnNch+a₂ s½/cosθ+a₃ cosθ+a₄+a₅ /(LnNch+a₆ LnNμ)

    where Nch is the EAS size, Nμ is a truncated (Rμ<50m) number of EAS muons with energies Eμ>5 GeV, s is the EAS age parameter and θ is the zenith angle of shower core (workshop GAMMA2004).


    Investigation of the High Energy Galactic Gamma Rays flux by the GAMMA Detector
    Determination of Gamma Showers Selection Efficiency

    Gamma detector distinctly sees the high energy Galactic gamma rays at energy 1014≲Eγ≲1015eV
    with frequency ƒ~10-3 EAS-1 and C.L. 99%. (presented to the GAMMA workshop 2004)