Results of the study of variations of cosmic ray muon flux at the Earth surface during Forbush decreases registered in 2007–2018 by means of the muon hodoscope URAGAN are presented. The dynamics of ...the amplitude spectral index at different stages (the decrease, the minimum, and the recovery), which correspond to different phases of the influence of heliospheric disturbances on the flux of cosmic rays for the period 2012 to 2018, is considered. To investigate possible regularities in the behavior of the projection of the relative local anisotropy vector of the muon flux to the South and to the East (
r
S
and
r
E
) during 2007–2018, the distributions of these parameters for four phases (immediately before FD, decrease phase, minimum phase, recovery phase) were calculated.
The existence of an excessive number of multimuon events observed in many experiments at ultrahigh EAS energies (above 10
17
eV) relative to calculations cannot be explained using modern models of ...hadronic interactions. One way of solving the problem of muon excess is to study the energy characteristics of the EAS muon component. Results are presented from measurements of muon bundle energy characteristics over 7 years of observations. The experimental dependences are compared to results from simulation done with the CORSIKA software package.
The most powerful coronal mass ejection of the 24th solar cycle took place on the opposite side of the Sun on July 23, 2012 and had no geomagnetic consequences. Nevertheless, as a result of passing ...of the ejection through the heliosphere, variations of galactic cosmic rays flux were observed on the Earth. These variations were registered by the muon hodoscope URAGAN (MEPhI, Moscow). Muon flux angular distributions on the Earth’s surface are reported and analyzed.
The method of two-dimensional filtering of modulated matrix data sequences is proposed. The structure of a two-dimensional filter based on operations of element-by-element matrix multiplications is ...developed. An application of the two-dimensional filtering of the URAGAN muon hodoscope matrix data sequence for the elimination of muon flux diurnal modulations is discussed.
Forbush effects caused by powerful X-class solar flares are studied using URAGAN muon hodoscope data for the period 2007–2019. The URAGAN muon hodoscope registers the cosmic ray muon flux on the ...Earth’s surface from different directions simultaneously. This allows study of the energy, angular, and space–time characteristics of variations in the cosmic ray muon flux during Forbush effects. The dependence of the measured Forbush effects on the parameters of heliospheric and geomagnetic disturbances is analyzed.
A description of the detection and data-acquisition systems of the Cherenkov water calorimeter of the NEVOD Experimental Complex, which is a unique scientific facility located on the Earth’s surface, ...is presented. In the development of these systems, a solution is sought to the problem of measuring the energy of cascade showers initiated by single muons and the energy deposited by high-multiplicity muon bundles in a wide energy range.
Coronal mass ejections (CMEs) are the brightest manifestations of solar activity. During periods of higher solar activity, dozens of ejections are observed daily and affect cosmic ray fluxes in ...interplanetary space. Observation of CMEs is usually carried out by means of various satellite apparatuses. In this work, features of the investigation of coronal mass ejections that are detected in the muon flux by the ground-based URAGAN muon hodoscope operating as a part of the Experimental complex NEVOD at the Moscow Engineering Physics Institute are discussed. Results of studying the anisotropy of the cosmic ray muon flux during the CMEs of 2016 are presented.
Energy characteristics of the muon component of extensive air showers (EASes) are investigated at the NEVOD experimental complex in order to solve the problem of a detected excess of muons in EASes ...at ultrahigh energies, relative to simulation results. The dependences of the energy deposit of muon bundles on the zenith angle and the local muon density are obtained for primary energies of 10–1000 PeV. The results from comparing the data to simulations performed with the CORSIKA program are presented.
An experiment on the measurements of the energy deposit of inclined cosmic ray muon bundles is being conducted at the experimental complex NEVOD (MEPhI). The complex includes the Cherenkov water ...calorimeter with a volume of 2000 m3 and the coordinate-tracking detector DECOR with a total area of 70 m2. The DECOR data are used to determine the local muon densities in the bundle events and their arrival directions, while the energy deposits (and hence the average muon energy loss) are evaluated from the Cherenkov calorimeter response. Average energy loss carries information about the mean muon energy in the bundles. The detection of the bundles in a wide range of muon multiplicities and zenith angles gives the opportunity to explore the energy range of primary cosmic ray particles from about 10 to 1000 PeV in the frame of a single experiment with a relatively small compact setup. Experimental results on the dependence of the muon bundle energy deposit on the zenith angle and the local muon density are presented and compared with expectations based on simulations of the EAS muon component with the CORSIKA code.
Results are presented from analyzing experimental data on 0.1–10 TeV cascade showers generated by muons in the NEVOD Cherenkov water detector. The procedure for selecting and reconstructing the ...parameters of events with cascades in the detector volume is discussed. Results are presented from measurements of the zenith angle distribution of cascades for different energies. The measured distributions are compared to results from calculations.