Dependence of cosmic ray component in background of atmosphere surface from solar magnetic activity

Abstract

Using Geant4 toolkit the changes of the flux density and of the dose rates of the secondary cosmic radiation at the heights up to 50 m from the land surface (at a depth of atmosphere about 1030 g/cm²) and depending on solar magnetic activity were estimated. For changes of Wolf’s number (sunspots) in the range of 0 — 200 the flux density of reflected from air and the soil g- and b- particles changes from 5.7 to 7 and 0.10 – 0.13 m-²s-¹ respectively, for energy from 0 keV to several units of GeV in the ground atmosphere on one meter from the earth. These estimates are much lower than those estimates, for radiation created by the soil and atmospheric radionuclides, which had been received earlier. In comparison with a contribution of radionuclides of the soil of flux density of secondary cosmic radiation about 0.01% and 0.1%, for gamma and beta radiation respectively. The received assessment of the dose rate transferred by secondary cosmic radiation about 0.7% from rate of the formed by soil’s radionuclides. In addition, an assessment of change in characteristics of secondary cosmic radiation depending on the level of solar magnetic activity presented in work. It is found that change of radiometric and dosimetric characteristics of secondary cosmic radiation depending on solar magnetic activity can be over 40%. It well repeats the changes of a dose found during a transcontinental flight. We found that the optimal average energy of spectrum of primary protons is 2.7 GeV. We can apply this feature to standards to find the most intensive periods of a secondary space gamma radiation and to use them in the experimental data, without involving the use of the Geant4. We have not found any significant contribution of secondary cosmic radiation reflected from the earth’s surface. This allows us to refuse from taking into account the soil layer in the model.

Keywords

• simulation
• cosmic radiation
• geant4
• monte-carlo
• atmosphere
• background radiation
• wolf’s numbers
• моделирование
• космическое излучение
• geant4
• монте-карло