On energetic particles in space

Abstract

On energetic particles in spaceParticles energized above the Earth's atmosphere provide unique informations about specific physical processes in the outer space. This is an attempt to present a short review of the knowledge of the characteristics of the cosmic energetic particles in wide energy range as observed on the ground, in the atmosphere, on Earth's satellites and on space probes. However, the review is related only to selected problems of cosmic ray physics and space physics. The bias is especially towards lower energies. After the historical introduction the features of primary cosmic rays is described. The heliosphere, in which the direct measurements of cosmic energetic particles takes place, is modulating the primary flux by magnetic fields controlled by the processes on solar surface and, is contributing to the low energy population by acceleration via transient processes as well as by solar flares. Important processes occur near the heliospheric outer boundary from where recently the space probes provided new information. Heliospheric influence is summarized in the third chapter. Another important object, the magnetosphere, is changing trajectories of incoming charged particles by "magnetospheric optics". Magnetosphere iself by the acceleration, transport, trapping as well as losses of lower energy particles alternates significantly the radiation environment near the Earth. The knowledge of particle population for which the condition of trapping are suitable in magnetospheres of giant planets of solar system, have increased thanks to space probes and planetary orbiters. Chapter four summarizes few important points of the magnetospheric influence on energetic particles. The measurements of temporal variability of the flux, energy spectra and angular distribution of cosmic ray particles influenced by solar-terrestrial effects, provides a unique tool for monitoring and eventual prediction of space weather effects, in addition to the investigations of the photon flux of various wavelength from the Sun, solar wind plasma and the magnetic field in interplanetary space. This is the main part of the chapter five.