Comments on multiple scattering of high-energy muons in thick layers

We describe two independent methods to calculate the angular distribution of muons after traversing a thick scatterer due to multiple Coulomb scattering. Both methods take into account the nuclear size effect. We demonstrate a necessity to account for the nucleus extension as well as incoherent scattering on atomic electrons to describe the muon scattering at large angles in thick matter layers. The results of the two methods of calculations are in good agreement.Comment: 22 pages, 5 figures, submitted to Nucl. Instrum. and Met

Study of Characteristics of the Quasi-spherical Measurement Modules of the Cherenkov Water Calorimeter NEVOD

AbstractThe use of quasi-spherical modules with several PMTs with flat photocathodes in Cherenkov water detectors is discussed. Properties of the response of such modules are examined. The characteristics of the quasi-spherical module with six PMTs that is used in the Cherenkov water calorimeter NEVOD are considered. The results of studying the isotropy of the amplitude response of this module and the quality of reconstruction of light direction with a single module and with a group of modules are demonstrated

Ultra-high energy cosmic ray investigations by means of EAS muon density measurements

A new approach to investigations of ultra-high energy cosmic rays based on the ground-level measurements of the spectra of local density of EAS muons at various zenith angles is considered. Basic features of the local muon density phenomenology are illustrated using a simple semi-analytical model. It is shown that muon density spectra are sensitive to the spectrum slope, primary composition, and to the features of hadronic interaction. New experimental data on muon bundles at zenith angles from 30 degrees to horizon obtained with the coordinate detector DECOR are compared with CORSIKA-based simulations. It is found that measurements of muon density spectra in inclined EAS give possibility to study characteristics of primary cosmic ray flux in a very wide energy range from 10^15 to 10^19 eV.Comment: 7 pages, 7 figures. Presented at CRIS-2006, Catania, Italy, May 29 - June 2, 2006. Accepted for publication in Nucl. Phys. B (Proc. Suppl.

New technique and results of cosmic ray investigations in the energy interval 1015–1019 eV

New technique of EAS investigations based on the measurements of local muon density spectra (LMDS) is developed. Application of this method to investigations of inclined EAS allows exploration of CR energy interval from 10 15 to 10 19 eV by means of a relatively small detector with area ∼100m 2 due to very strong dependence of EAS muon density on zenith angle. During 2002-2007, long-term NEVOD- DECOR experiment (about 20,000h live time) was conducted, and more than two million muon bundles in zenith angle interval 30-88 degrees were registered. Comparison of experimental data with results of CORSIKA-based simulations showed that the new method is sensitive to all main peculiarities of CR energy spectrum: the knee, increase of the energy spectrum slope with energy, the second knee. But the observed progressive excess of muon bundles with the increase of primary CR energy in comparison with simulations (even for pure iron composition) can indicate the appearance of new processes of muon generation. In this case, for correct investigations of EAS, the experimental arrays must be supplemented by detectors which can measure or evaluate the energy of muons

LARGE AREA HODOSCOPES FOR MUON DIAGNOSTICS OF HELIOSPHERE AND EARTH'S MAGNETOSPHERE

Muon diagnostics is a technique for remote monitoring of active processes in the heliosphere and the magnetosphere of the Earth based on the analysis of angular variations of muon flux simultaneously detected from all directions of the upper hemisphere. To carry out muon diagnostics, special detectors – muon hodoscopes – which can detect muons from any direction with good angular resolution in real-time mode are required. We discuss approaches to data analysis and the results of studies of various extra-terrestrial processes detected by means of the wide aperture URAGAN muon hodoscope

Energy spectrum of cascade showers initiated by cosmic ray muons in the Cherenkov water detector

Results of analysis of experimental data on cascade showers with energies of 0.1 – 10 TeV initiated by muons in the Cherenkov water detector NEVOD are presented. The method of selection and reconstruction of cascade parameters in the volume of the detector is discussed. Experimental distributions of cascade axes in zenith angle and energy spectrum of cascades are obtained. The measured distributions are compared with results of calculations

Energy spectrum of cascade showers initiated by cosmic ray muons in the Cherenkov water detector

Results of analysis of experimental data on cascade showers with energies of 0.1 – 10 TeV initiated by muons in the Cherenkov water detector NEVOD are presented. The method of selection and reconstruction of cascade parameters in the volume of the detector is discussed. Experimental distributions of cascade axes in zenith angle and energy spectrum of cascades are obtained. The measured distributions are compared with results of calculations

New technique and results of cosmic ray investigations in the energy interval 10

New technique of EAS investigations based on the measurements of local muon density spectra (LMDS) is developed. Application of this method to investigations of inclined EAS allows exploration of CR energy interval from 1015 to 1019eV by means of a relatively small detector with area ∼100m2 due to very strong dependence of EAS muon density on zenith angle. During 2002–2007, long-term NEVOD-DECOR experiment (about 20,000 h live time) was conducted, and more than two million muon bundles in zenith angle interval 30–88 degrees were registered. Comparison of experimental data with results of CORSIKA-based simulations showed that the new method is sensitive to all main peculiarities of CR energy spectrum: the knee, increase of the energy spectrum slope with energy, the second knee. But the observed progressive excess of muon bundles with the increase of primary CR energy in comparison with simulations (even for pure iron composition) can indicate the appearance of new processes of muon generation. In this case, for correct investigations of EAS, the experimental arrays must be supplemented by detectors which can measure or evaluate the energy of muons