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The paper reports the results of simulation of cosmic ray proton transport through Earth’s atmosphere. The main objective of this work is to obtain characteristics of secondary particle fluxes at different altitudes and to convert them to equivalent dose values. The technique for the conversion is based on numerical simulation of interaction between the particles and an anthropomorphic phantom. The paper examines two cases, using a model source of primary proton spectra as input parameters, which correspond to both purely galactic cosmic rays and solar cosmic rays. The computational results are tabulated for the altitude range from 0 km to 11 km above sea level; the upper range value corresponds to the flight altitude of civilian airliners. These results are shown to agree well with the results obtained by other research teams.

At present, cosmic ray (CR) physics uses a considerable variety of methods for studying CR characteristics, and both primary and secondary fluxes, respectively. Experimental methods make the main contribution, using various types of detectors, but numerical methods increasingly complement it due to the active development in computer technology. This approach provides researchers with the most extensive information about details of the process or phenomenon and allows us to make the most competent conclusions. This paper presents a concept of the RUSCOSMIC software package based on the GEANT4 toolkit and representing a range of different numerical models for studying the CR passage through a matter of different systems. The obtained results represent response functions of the main radiation detectors as well as some typical characteristics of secondary CR fluxes. Comparative results also show the operation of the module verifica-tion of calculations with experimental data.

This paper explores the applied use of the RUSCOSMICS software package [http://ruscosmics.ru] designed to simulate propagation of primary cosmic ray (CR) particles through Earth’s atmosphere and collect information about characteristics of their secondary component. We report the results obtained for proton fluxes with energy distributions corresponding to the differential spectra of galactic CR (GCR) and solar CR (SCR) during ground level enhancement (GLE) events GLE65 and GLE67. We examine features of the geometry of Earth’s atmosphere, parametrization methods, and describe a primary particle generator. The typical energy spectra of electrons obtained both for GCR and for GLE65 provide information that allows us to quantitatively estimate the SCR contribution to the enhancement of secondary CR fluxes. We also present altitude dependences of ionization rate for GCR and both the GLE events for several geomagnetic cutoff rigidity values. The conclusion summarizes and discusses the prospects for future research.

The complex facility for continuous monitoring of various components of secondary cosmic rays was developed in the Polar Geophysical Institute. Increases in gamma-radiation during precipitation are found to occur during the year regardless of a season. As shown in a series of experiments, there is no precipitation pollution by any radionuclides of natural or artificial origins. Radiation spectrum does not have any characteristic lines of elements. The mechanism which satisfactorily describes this phenomenon was proposed.