Cosmic Ray research at high altitude stations on Mt. Aragats, Armenia, was founded by famous Armenian physicists, Alikhanyan brothers, in 1943. Research facilities are located on two high-altitude stations on Mt.Aragats, Nor-Amberd Station and Aragats Station, and at CRD headquarters at Alikhanyan Physics Institute, Yerevan.

Cosmic Ray Division (CRD) is a center of excellence for research on the:

1. Origin and acceleration mechanisms of Galactic Cosmic Rays (GCR); experiments with surface arrays measuring Extensive Air Showers (EAS).

Discovery of the features of Galactic Cosmic Rays spectra such as: very sharp change of the power spectra index (~1) for the light nuclei group at 2-4 PeV and no pronounced change for the heavy nuclei group (at least for energies 20-30 PeV) (Chilingarian et al., 2004, 2007a); this discovery of charge dependent “knee” in energy spectra pointed on the shock acceleration initiated by the supernovae blasts as most probable mechanism of particle acceleration. Further detailed mapping of the supernovae shell rims made by the orbiting X-ray observatories and surface atmospheric Cherenkov Telescopes (ACT) confirms possibility of particle acceleration in supernovae shells.

2. Particle acceleration in the vicinity of the Sun and their maximal energy.

Discovery of energetic protons (with energies greater than 20 GeV) accelerated I vicinity of Sun at 20 January, 2005 during Ground Level Enhancement (GLE) event N 69 (Bostanjyan et al., 2007, Chilingarian &Reymers, 2007, Chilingarian, 2008).

3. Space Weather (SW) research and continuous monitoring of changing fluxes of secondary cosmic rays at high mountain altitudes using particle detectors of the Aragats Space Environmental center (ASEC), at 1000, 2000 and 3200 m altitudes.

Uninterruptible registration of the one of major geophysical parameters: cosmic ray fluxes incident on Earth’s surface; registration of Ground Level Enhancements (GLE), Radiation and Geomagnetic Storms (GMS), Forbush decreases (Fd) during the declined phase of the 23-rd solar cycle. Development of the correlation analysis of depletions (or enhancements) of neutral and charged secondary cosmic ray fluxes during solar transient events.

4. Development of worldwide network of particle detectors called SEVAN (Space Environmental Viewing and Analysis Network) and fabrication of new types of particle detectors and DAQ electronics for secondary cosmic ray flux monitoring.

The development of the SEVAN network aims to improve fundamental research of space weather conditions and to provide short and long-term forecasts of dangerous consequences of space storms. The United Nations Basic Space Science Observatory Development program and International Heliophysical Year 2007 (IHY 2007) recognized SEVAN as one of the main activities carried out within the framework of the program of employing Space Weather detectors in developing countries to involve these countries in space research.
5. High Energy phenomena in low atmosphere
Despite multiyear research, many questions on high energy phenomena connected with thunderstorms fail making convincing experimental detection and theories and models fail to  explain how lightning works.   Measured fluxes of energetic particles, as well as broad band radio emission, can provide necessary information for the new theories of the physical processes involved in the thunderstorm and lightning.  The Aragats Space Environment Center facilities  regularly measure fluxes of neutral and charged secondary cosmic rays incident on the Earth’s surface. In 2009 we simultaneously detected  very large fluxes of electrons, gamma-rays and neutrons correlated with thunderstorm activity. During the period of the count rate enhancements lasting tens of minutes, millions of additional particles were detected. First time measured energy spectra of electrons and gamma-rays  rapidly fell and vanished at ~ 30-40 MeV.

6. Development of the statistical methods and data analysis software for the physical interpretation of multivariate data from complicated non-direct experiments in high energy astrophysics, including EAS and ACT experiment; Development of the interactive tools for the interactive multivariate data display and analysis (Konopelko et al., 2006, Bock et al., 2004, Antoni et al., 2003, Chilingarian & Vardanyan, 2003).

Development of the multidimensional cuts (“supercuts”) method for revealing signal from point sources with imaging ACTs; Introducing of the “event-by-event” analysis technique for EAS experiments; classification of the EAS by primary nuclei; reconstructing partial spectra of GCRs; CRD’s Data Visualization Interactive Network (DVIN) won the World Summit on Information Society award in 2003 in Geneva.

Topics of possible cooperation with Cosmic Ray Division (CRD) 

  • Cooperation in instrumentation and measuring of secondary fluxes of cosmic rays and other Geospace parameters for basic Space research, developing forewarning services by participating in the ASEC activities in Armenia and by installing SEVAN detector and participating in the world-wide network (see the ASEC and SEVAN pages in: http://Aragats.am ).
Modern scientific and technical infrastructure at mountain research stations of Yerevan Physics Institute along with comfortable accommodation possibilities provide unique possibilities to perform wide range of experiments in the environmental science and high energy astrophysics.

  • 2010 campaign on multivariate investigation of the high energy phenomen in thunderstorms, including:

Low threshold detection of electrons, muons, gamma-rays and neutrons;
Location of lightnings time and place;
VLF and FM radio measurements with sampling rate not worse than 10 KHz;
Measurements of the electrical and magnetic fields;
Video- monitoring of sky between Aragats and Ararat;
Infrared and ultraviolent measurements. 
  • Participation in the ANI-new project of detection of ultra-high energy cosmic rays (1017 - 1019 eV) at Aragats Cosmic Ray Observatory (Chilingarian et al., 2007c, see also presentation at European Cosmic Ray Symposium, Kosice, 2008, http://ecrs2008.saske.sk/presentations.php)
The proposal of creating Aragats Cosmic Ray Observatory include not only new type of EAS detectors, measuring neutron and charged particles of the Extensive Air Showers (EAS), but also arrays of antennas to detect radio-bursts from EAS particles; optical robotic telescopes for detecting afterglow of GRB; and arrays of new-type of ACTs of post-GLAST (Enriko Fermi telescope) era.

Reference

  1. A. Chilingarian, G. Hovsepyan, K. Arakelyan, S. Chilingaryan, V. Danielyan, K. Avakyan, A. Yeghikyan, A. Reymers, S. Tserunyan. (2008), Space Environmental Viewing and Analysis Network (SEVAN), Earth, Moon, and Planets, in press.
  2. Chilingarian A.A. (2008), Statistical study of the detection of solar protons of highest energies at 20 January 2005, Advances of Space Research, in press.
  3. A. Chilingarian and A. Reymers, Investigations of the response of hybrid particle detectors for the Space Environmental Viewing and Analysis Network (SEVAN) (2008), Ann. Geophys., 26, 249-257.
  4. A.Chilingarian et al, Study of EAS and Primary Energy Spectra by MAKET-ANI Detector on Mountain Aragats, Astroparticle Physics 28 (2007a) 58-71.
  5. A. Chilingarian, L. Melkumyan, G. Hovsepyan, A. Reymers, The response function of the Aragats Solar Neutron Telescope, Nuclear Instruments and Methods in Physics Research A 574 (2007b) 255-263
  6. A.Chilingarian, G.Hovsepyan, V.Ivanov, et al., Research on Galactic Cosmic Rays from “knee” to the “cutoff” at the Aragats Cosmic Ray Observatory (Proposal of New ANI project), (2007c)Proceedings of the International Cosmic Ray Workshop “Aragats2007”, 130-137).
  7. Bostanjyan, N.K. et al., On the production of highest energy solar protons at 20 January 2005, J. Adv. Space Res. 39 (2007) 1456-1459.
  8. A.A. Chilingarian, A.E. Reymers, Particle detectors in Solar Physics and Space Weather research, Astroparticle Physics (2007), Astropart. Phys., 27, 465-472
  9. A Konopelko, A Chilingarian and A Reymers, Study on cosmic ray background rejection with a 30 m stand-alone IACT using non-parametric multivariate methods in a sub-100 GeV energy range, J. Phys. G: Nucl. Part. Phys. 32 (2006) 2279.2291
  10. A. Chilingarian, G. Gharagyozyan, G.Hovsepyan, G.Karapetyan, Statistical Methods for Signal Estimation of Point Sources of Cosmic Rays, Astroparticle physics 25, pp 269-276
  11. A.Chilingarian for the ASEC team, (2005) Correlated Measurements of Secondary Cosmic Ray Fluxes by the Aragats Space- Environmental Center Monitors,NIM-A, 543, 483-496
  12. R.K. Bock, A. Chilingarian, et. al.(2004), Methods for Multidimensional Event Classification: a Case Study Using Images from a Cherenkov Gamma-Ray Telescope, Nuclear Instruments and Methods in Physics Research A516, pp. 511-528.
  13. A.Chilingarian, K.Avakyan et. al, Aragats Space-Environmental Center: Status and SEP Forecasting Possibilities, Journal of Physics G:Nucl.Part.Phys., Vol.29 (2003), pp 939-952.
  14. A. Chilingarian, G. Gharagyozyan, G. Hovsepyan, S. Ghazaryan, L. Melkumyan, and A. Vardanyan,(2004) Light and Heavy Cosmic-Ray Mass Group Energy Spectra as Measured by the MAKET-ANI Detector, The ApJ letters, 603,pp. L29-L32.
  15. T.Antoni, et al. for the KASCADE collaboration, Preparation of Enriched Cosmic Ray Mass Groups with KASCADE Astroparticle Physics Vol.19 (2003), pp.715-728.
  16. A. A. Chilingarian, A.A. Vardanyan, Multivariate Methods of Data Analysis in Cosmic Ray Astrophysics, Nuclear Instruments & Methods (NIM), Vol.502/2-3 (2003), pp 787-788.