| 2010-10-21 12:48:03 |
Aragats physicists publish an important discovery about thunderstorms
Cosmic Ray research on Mt. Aragats started in 1943 by the physicists Artem and Abraham Alikhanians. Since then researches at the Cosmic Ray Division (CRD) of the Alikhanyan National Laboratory have continued at two high altitude research stations: on Mt. Aragats, as well as the headquarters in Yerevan. CRD is one of the world's largest institutions investigating many aspects of cosmic ray physics and which most recently started researches on the particle acceleration in the Earth’s atmosphere.These studies were initiated by the discovery of the Terrestrial gamma-ray flashes (TGFs) – microsecond blasts of gamma rays, discovered in 1994 by the Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory. Despite these bursts of energetic radiation appeared to be the confirmation of Lord Wilson's 70 years old predictions, the physical picture of TGFs as short bursts of energetic photons was incomplete and required further study.
The new evidence of enormous particle accelerators in the upper atmosphere comes from surface particle detectors located at mountain altitudes just under thunderclouds. Aragats led to establishing the existence of long-lasting particle multiplication and acceleration mechanisms in thunderstorm atmospheres. For the first time, Aragats physicists measured the energy spectra of electrons and gamma rays reaching the Earth’s surface that resulted from particle avalanches produced in thunderstorm atmospheres. During the event on September 19, 2009, huge fluxes of electrons, gamma-rays and neutrons, as well as short particle bursts consisting of millions of particles distributed over a large areawere detected, manifesting so called RREA (relativistic runaway electron avalanche) process.
In 2010, new particle detectors were designed and fabricated in the Cosmic Ray Division of Alikhanyan National Laboratory and will soon start operating at an altitude of 3250 m. New precise devices measuring electrical and magnetic fields, aswell as lightning detectors are ready to make joint observations of the high energy phenomena in future thunderstorm atmospheres. Colleagues from The Skobeltsin Nuclear Physics Institute of Moscow State University will install unique optical instruments for monitoring of thundercloudsin September. New results from Aragats as well coupled with from the observations from orbiting gamma observatories and surface measurements from other centers will be discussed on the international conference “Thunderstorms and Elementary Particle Acceleration (TEPA-2010). TEPA 2010 will start on September 7 on the slopes of Mt. Aragats in Nor Amberd. Joint collaborative efforts of physicists from many countries will finally solve the enigma of lightning!
