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For the purposes of a study of hadron component of an extended air shower (EAS), two detectors of cosmic rays (CR) were joined at the Baksan Neutrino Observatory. They are an EAS array detector (the "Carpet") and a neutron monitor (NM). Due to the versatility of a new recording system a master-pulse, which comes from the "Carpet" and marks to occurring of EAS, is joined to NM data. After processing of the huge data set it is found that the time of EAS influence on NM is less than 1 ms. The distribution of time intervals between pulses in the first millisecond after EAS onset is essentially different from the background and shows presence of two processes with characteristic times 45 and 230 µs. [ABSTRACT FROM AUTHOR]

By now real time systems of data collection of neutron monitor network have been created. The main goal of such systems is early detection of dangerous events of space weather, such as GLE, caused by arrival to the Earth of relativistic solar protons. Characteristics of these particles are determined from the data of the worldwide neutron monitor network by methods of GLE modeling. Traditional GLE modeling requires data of no less than 30-35 stations and takes a long time of computations. We developed a truncated technique of solar proton spectrum determination by data of limited number (20-25) of neutron monitor stations and with a simplified procedure of computations adapted for operative diagnostics of relativistic solar protons just arriving to the Earth. Possibilities of this truncated GLE modeling for the early forecast of radiation-dangerous fluxes of solar particles with moderate energies are also shown. [ABSTRACT FROM AUTHOR]

Increases in intensity of X-radiation in the ground layer of the atmosphere observed during various atmospheric phenomena in two points: Apatity (Kola Peninsula) and Barentsburg (Spitsbergen) have been studied. A clear relationship between the increases and such atmospheric phenomena as rain and snowfall has been found. It is shown that these increases are not connected with any radionuclides. This research suggests that the principal cause of high-energy photons increase during precipitations are bremsstrahlung X-rays created by energetic electrons accelerated by electric fields in the clouds. A possible mechanism of generation of X-ray photons is discussed. [ABSTRACT FROM AUTHOR]

With the developed by the authors of a ground level enhancements events (GLE) modeling technique, the modeling study of 35 large GLEs for the period 1956 - 2006 has been carried out. The basic characteristics of relativistic solar protons (RSP) are obtained: a rigidity (energetic) spectrum, anisotropy axis direction, and pitch angle distributions for each event. It is shown that in nearly all events there existed two components (population) of relativistic solar particles: prompt and delayed. The prompt component (PC) prevails in the beginning of the event. It is characterized by an impulsive profile, strong anisotropy and exponential energetic spectrum. The delayed component (DC) dominates during maximum and decline phases of the events. It has a gradual intensity profile, moderate anisotropy and a power law energetic spectrum. The analysis of the large number GLE shows the value of a characteristic energy in the exponential spectrum of PC has rather stable meaning ~0.5 GeV and well agrees with the spectrum of protons accelerated in an electric field arising during the magnetic reconnection in the solar corona. The value of a spectral exponent of the power law spectrum of DC is distributed from 4 up to 6 with most at 5. This is close to the simulated spectrum arising in the process of stochastic acceleration in turbulent solar plasma. [ABSTRACT FROM AUTHOR]

Based on a huge data set acquired with a unique recording system, multiplicity events M = 4 - 50 on a neutron monitor have been analyzed in detail. The multiplicity events are recorded in detail for the first time, their structure being examined. The multiplicity processes in a neutron monitor have been numerically simulated by a toolkit GEANT4. Analysis of neutron monitor data with high temporal and spatial resolution reveals that most multiplicity events involving more than three adjacent counter tubes are due to local hadronic air showers with characteristic dimensions of size 1 - 3 m and duration of ~ 1 ms. [ABSTRACT FROM AUTHOR]

The characteristics of hadrons with Eh > 50 MeV in EAS have been obtained. The measurements were performed at the CARPET-2 extensive air shower array. For showers with E0 > 6 ⋅ 1013 eV the duration of hadronic cascade in NM has been estimated. The dependence of the mean neutron multiplicity in the neutron monitor on the total number of the change particles for EAS with Ne = 105 - 107 at a distance of 17 - 30 m from EAS axis has been measured. [ABSTRACT FROM AUTHOR]

The characteristics of hadrons with Eh > 50 MeV in EAS have been obtained. The measurements were performed at the CARPET-2 extensive air shower array. For showers with E0 > 6 ⋅ 1013 eV the duration of hadronic cascade in NM has been estimated. The dependence of the mean neutron multiplicity in the neutron monitor on the total number of the change particles for EAS with Ne = 105 - 107 at a distance of 17 - 30 m from EAS axis has been measured. [ABSTRACT FROM AUTHOR]