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Small and middle size surface detectors measuring extensive air showers (EAS) initiated by primary cosmic rays (PCR) incident on terrestrial atmosphere have been in operation for the last 50 years. Their main goal is to explore the ‘‘knee’’ in all particle spectrum to solve the problem of cosmic ray (CR) origin and acceleration. The recent achievements of atmospheric Cherenkov telescopes and X-ray space laboratories, establishing the supernova remnants (SNRs) as a source of hadronic cosmic rays, pose stringent conditions on the quality of EAS evidence. After establishing the existence of the ‘‘knee’’ itself, the most pronounced result from EAS studies is the rigidity dependent shift of the knee position to the highest energies. This feature was first observed by separation of the primary flux in different mass groups in MAKET-ANI, EAS-TOP and KASCADE experiments. The MAKET-ANI detector is placed on Mt. Aragats (Armenia) at 3200 m above the sea level (40� 25 0 N, 44� 15 0 E). More than 1.3 · 10 6 showers with size greater than 10 5 particles were registered in 1997–2004. The detector effectively collected the cores of EAS, initiated by primaries with energies of 10 14 –10 17 eV. After proving that the quality of the EAS size and shape reconstruction was reasonably high, we present the lateral distribution function (LDF) for distances from 10 to 120 m from EAS core and EAS size spectra in 5 zenith angle intervals. We use CORSIKA simulations to present the energy spectra. The results from the MAKET-ANI experiment on the energy spectra of the ‘‘light’’(p + He) and ‘‘heavy’’ (O + Si + Fe) nuclear groups are compared to the spectra obtained by balloon experiments and to other available spectra. � 2007 Elsevier B.V. All rights reserved.

Standard models of cosmic-ray origin link the space accelerators of our Galaxy to the supernova remnants (SNRs)—expanding shells driven by very fast blast waves, usually with gamma-ray pulsars near the morphological center. Energy spectra of fully stripped ions with charges from Z = 1 to Z = 26 can provide clues to the validity of the standard model. Unfortunately, smeared data from the extensive air shower experiments do not provide enough information for such ion "spectroscopy." Nonetheless, the measurement of energy spectra of two or three broad mass groups (so-called light, intermediate, and heavy) will allow us to prove or disprove the "rigidity-dependent" acceleration. Recently, using multidimensional classification methods, the "all-particle" spectra from the MAKET-ANI experiment on Mount Aragats, in Armenia, was categorized into two distinct primary mass groups. We present, for the first time, the light and heavy nuclei spectra from the MAKET-ANI experiment.

The Solar Environment Center located on Mt. Aragats will provide real-time monitoring and forecasting of the extreme Geomagnetic and Radiation Events. Two neutron monitors, a muon telescope and a Solar scintillation telescope operating on Aragats research stations will provide accurate detection of very low fluxes of the most energetic Solar particles and modulation effects of Solar events. The correlation of the Solar Energetic Phenomena with modulations of the Galactic Cosmic Ray flux and direct detection of the high-energy protons and neutrons emitted during Coronal Mass Ejection provide firm grounds for specification and forecasting of the effects of tremendous explosions on the Solar surface. Consequently ground observation of the variations of Cosmic Ray fluxes make it possible to issue alerts to avoid imminent hazard of upcoming Geomagnetic and Radiation Storms.

The results of probing the radiation environment on board different civil aviation planes with singletype detectors (nuclear emulsions), with particular emphasis to the cosmic radiation flux measured inside aircraft, are presented. The measurement results make it possible to find the absorbed and equivalent doses induced by the cosmic radiation neutrons and charged particles.