The Behavior of the Mean Multiplicity Coefficients of ASEC Neutron Monitors During Thunderstorm Activity Armen Hovhannisyan

Aragats Neutron Monitor

3 Dead Times of Neutron Monitor

Mean Multiplicity Coefficient

Nucleon double counting effect

Correlation Matrix of ArNM – Dead Time 1250mcs Det * * * * * * * * * * * * * * * * * *

Estimated Mean Multiplicities Section1Section2Section3NM median ANM1.43± ± ± NANM1.44± ± ±

The dependence of mean multiplicity on the cutoff rigidity (measurements by ship borne 3NM-64 of IQSY type in December 1966 – April 1967, Kodama & Ishida, 1967). By open circles are denoted mean multiplicities of the ArNM and NANM

Mean Multiplicity and EAS Average number of > 4σ spikes: 4±2 Expected Number of > 4σ spikes according to gaussian( ) distribution: 0.1 A.Chilingarian G. Hovsepyan, E. Mamidjanyan, Study of Extensive Air Showers and Primary Energy Spectra by MAKET-ANI Detector on Mountain Aragats, Astroparticle Physics, 28, pp 58-71, 2007.

Cross Sections of Photonuclear Reactions with air Cross Section of Photo Nuclear Reaction of Photons with Nitrogen(continuous line) and Carbon(dotted line) Nucleus Cross Section of Photo Nuclear Reaction of Photons with Oxygen Nuclei

Distribution of Mean Multiplicities of ARNM During Thunderstorm Activity Multiplicity, m Nucleon Energy (Gev) NM C.J. Hatton, The Neutron Monitor, in J., G. Wilson and S.A. Wouthuysen (eds.), Progress in Elementary Particle and Cosmic-ray Physics, vol. 10, chapter 1, North Holland Publishing Co., Amsterdam, 1971

Conclusions The notion of the multiplicity, introduced several decades ago, despite its elegance did not become yet a basis of the physical analysis of any importance in the cosmic ray physics and space weather research. Here we introduce method of calculation of the mean multiplicity and demonstrate its relation to the high energy primary cosmic ray physics and to new observed high energy phenomena in the thunderstorm atmospheres. We demonstrate the “bursts” in the mean multiplicity time series measured by Aragats Neutron Monitor are connected with the incident Extensive Air Shower initiated by the primary particles with energies greater than 1 PeV and by the low energy neutron photo production by the gamma rays from the RREA process.