No abstract

A: The Experimental Complex (EC) NEVOD includes a number of detectors used to carry out basic research of cosmic rays (CR) and their interactions in the energy range 10 11 -10 19 eV and applied research of the heliosphere, magnetosphere and atmosphere of the Earth by the muonography method which is based on the analysis of spatial-angular variations of the muon flux generated by primary CR particles with energies of 10 9 -10 11 eV. The EC NEVOD is being constantly developed. Nowadays, it consists of three basic groups of experimental facilities unique in the world: the major facilities (Cherenkov water detector NEVOD, calibration telescope system -CTS, coordinate-tracking detector DECOR), the peripheral facilities (extensive air shower array NEVOD-EAS, distributed thermal neutron detector systems PRISMA and URAN), the muon hodoscopes for cosmophysical and geophysical investigations (TEMP and URAGAN). All detectors and installations of the first two groups are combined by a multilevel triggering system and the time synchronization system ensuring timestamping of registered multicomponent events. Today,

IntroductionThe influence of the solar activity on heliospheric and magnetospheric processes is studied with the use of various equipments placed on satellites as well as on the surface of the Earth. As a result of these studies, a vast experimental material has been accumulated and some of relationships between the processes occurring on the Sun and in the heliosphere and the magnetosphere of the Earth have been established. Application of cosmic rays for such studies is of a great importance since cosmic ray particles propagate with the speed close to the speed of light that far exceeds the rate of propagation of any heliospheric disturbances. The usage of the muon component generated by primary cosmic-ray particles for this purpose is of a special interest since muons maintain the direction of the primary particles. Muon hodoscope URAGAN [1] registers the flux of cosmic-ray muons on the surface of the Earth simultaneously from various directions that allows to carry out the spatial and angular measurements of cosmic ray modulation in near-Earth space and study the muon flux variation dynamics in a wide range of zenith and azimuth angles with a single device. This, in its turn, allows studying the anisotropy of the muon flux caused by various disturbances of the heliospheric origin, and anisotropy observations may provide additional information about the nature of these disturbances much earlier than these disturbances reach the space vehicles operating near the Earth.This work is a continuation of the research initiated in 2007 [2], but the technique of the analysis has been significantly modified. Variations of the anisotropy of the muon flux during 2011 which is characterized by a considerable increase of the solar activity have been analyzed.

No abstract

Abstract.Results of the study of variations of cosmic ray muon flux at the Earth surface during Forbush decreases (FD) registered in 2006 -2011 by means of muon hodoscope URAGAN both for the integral counting rate and for different angular intervals are presented. Dependences of the amplitude of the decrease of cosmic ray muon intensity on the energy of primary particles in the energy region above 10 GeV during different phases of the FD were obtained. On the basis of the analysis of spatial-angular distribution of muon flux, values of the horizontal projections of the local anisotropy vector were calculated and their dynamics was studied. Energy, angular and temporal characteristics of Forbush decreases determined from cosmic ray muon data are compared with basic parameters characterizing conditions of nearEarth space before and during FD.