Bagrat Mailyan, Alikhanian National Laboratory (Former YerPhI) The energy spectra of the thunderstorm correlated electron and   gamma-ray fluxes measured at Aragats Bagrat Mailyan, Alikhanian National Laboratory (Former YerPhI) 32nd ICRC, Beijing, China

How electrons can “runaway”? Courtesy of B. Carlson Friction on electrons in air at sea level. Shown as a function of electron energy. The axis on the right indicates the electric field strength required to produce a force on an electron equal to the frictional force. 32nd ICRC, Beijing, China

Runaway Breakdown or Relativistic Runaway Electron Avalanche TGFs and TGEs 32nd ICRC, Beijing, China

RREA Events – huge long lasting peaks in particle monitor time series 32nd ICRC, Beijing, China

Experimental Facilities of ASEC ASEC detectors include neutron monitor, scintillating detectors and electric field meters, which allow to measure thunderstorm effects on various particles species and get the spectra of particles. 32nd ICRC, Beijing, China

Outdoor detectors installed in 2010 (CUBE and STAND) Monte Carlo simulations of ASEC detectors were done. The passage of the thunderstorm correlated gamma-rays through the roof of the laboratory building and detectors was simulated. 32nd ICRC, Beijing, China

Energy deposit spectra for background cosmic rays and thunderstorm correlated particles detected on October 4, 2010 32nd ICRC, Beijing, China

Incident gamma-ray energy spectrum recovery The unfolding of the gamma ray spectrum above the roof of the MAKET building at altitude of 3200 m was made in the following way: A power spectrum with initial parameters randomly chosen from predetermined interval is generated; This spectrum is used to simulate traversal of gamma rays via roof and ASNT detector components to finally obtain simulated energy release spectrum; The obtained simulated spectrum is compared with experimental one; the discrepancy (quality function) and initial spectrum parameters are stored; If number of iterations is not fulfilled go to step 1. 32nd ICRC, Beijing, China

Gamma-ray energy spectrum recovery for October 4, 2010 thunderstorm event 32nd ICRC, Beijing, China

September 19, 2009 and October 4 , 2010 thunderstorm event gamma-ray spectra After 50 MeV cosmic ray background is prevailing. 32nd ICRC, Beijing, China

Simulations of RREA process Courtesy of Levon Vanyan 32nd ICRC, Beijing, China

September 19, 2009 thunderstorm event electron spectrum Using detectors with various energy thresholds the electron spectrum was estimated. Gamma-ray contamination of the electron spectrum and the electron spectrum just after the electric field is estimated by Monte Carlo methods. 32nd ICRC, Beijing, China

Background muon flux decrease 32nd ICRC, Beijing, China

Conclusions TGE gamma-ray and electron spectra can be described by power law exponential and law functions respectively. These fact put limits on atmospheric electrical field strengths. There are less electrons detected and the maximal energy of the measured electrons is smaller in comparison with gamma rays. Electrons loss their energy and attenuate in the air faster than gamma rays. Two processes - avalanche development (Runaway Breakdown) and simple acceleration (transformation) in the thundercloud field should contribute in TGE. 32nd ICRC, Beijing, China

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