Calculation of certain characteristics of extended air showers in the lower part of the atmosphere for large fluctuations of the elementary act

Inelastic interaction role in calculation of extended air shower characteristic

Relationships among Solar Activity, SEP Occurrence Frequency, and Solar Energetic Particle Event Distribution Function

Abstract The solar cycle 20-22 direct spacecraft measurement results are used to analyze the occurrence frequency and distribution function of solar energetic particle (SEP) events as dependent on solar activity. The analysis has shown that • the mean occurrence frequency of the SEP events with ≥30 MeV proton fluence sizes exceeding 10 6 is proportional to sunspot number, • the SEP event proton distribution functions for periods of different solar activity levels can be described to be power-law functions whose spectral form (spectral indices and cutoff values) are the same. The above results permit the following conclusions: a) to within statistical deviations, the total number of SEP events observed during any given time interval is proportional to the sum of mean-yearly sunspot numbers; b) large SEP events can occur to within quite a definite probability even during solar minima

Simulations of Galactic Cosmic Ray Impacts on the Herschel/PACS bolometer Arrays with Geant4 Code

The effects of the in-flight behaviour of the bolometer arrays of the Herschel/PACS instrument under impacts of Galactic cosmic rays are explored. This instrument is part of the ESA-Herschel payload, which will be launched at the end of 2008 and will operate at the Lagrangian L2 point of the Sun-Earth system. We find that the components external to the detectors (the spacecraft, the cryostat, the PACS box, collectively referred to as the `shield') are the major source of secondary events affecting the detector behaviour. The impacts deposit energy on the bolometer chips and influence the behaviour of nearby pixels. 25% of hits affect the adjacent pixels. The energy deposited raises the bolometer temperature by a factor ranging from 1 to 6 percent of the nominal value. We discuss the effects on the observations and compare simulations with laboratory tests.Comment: Experimental Astronomy, 2008, in pres

Cosmic ray particles with different LET values under various thicknesses of shielding in low altitude orbits: Calculations and Cosmos-2044 measurements

Fluxes of cosmic ray particles with different LET values were measured on board the COSMOS-2044 biosatellite under various thicknesses of shielding by stacks of CR-39 and nitrocellulose plastic nuclear track detectors (mounted outside the satellite). The component composition of the particles detected under shieldings of 0.1-2.5 g cm(exp -2) is verified by comparing experimental data with the results of model simulations of the fluxes of galactic cosmic ray particles and of radiation belt protons

Observation of nuclei with energies 8-30 MeV per nucleon in the Earth's magnetosphere at the altitudes 350 KM

Observations of the flux of nuclei with an energy of IO MeV per nucleon on the Salyut-7 Station in September 1984 are presented. The observed flux is smaller by a factor of 50 than the flux detected in May, 1981