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The results are presented of measurements high-energy particles in a customary manned space station orbit (a 350–450-km altitude, a 51.6° inclination; Salyut-6 and 7, MIR). The particles were recorded by the chambers composed of the Lavsan (polyethyleneterephtalate) solid-state nuclear track detector layers mounted outside a spacecraft for 1–3 years. A high resolution has been attained in the charge and energy spectra of 30– 200 MeV / n Fe group particles. The results of measuring the particle fluxes in the space station orbits are used to restore the initial particle energy spectra in terms of the models that describe the galactic and solar cosmic rays and their penetration to the Earth's magnetosphere. The analysis demonstrates a high effectiveness of the described methods when applied to quite a number of space physics problems.

The results of the numerical solution of the Fokker-Planck equation, describing radial diffusion of protons and heavy ions in the Earth's magnetosphere, are presented. Radial transport driven by fluctuations of the geomagnetic or the electric field, or a combination of both, was included in the solution. Coulomb interaction and charge exchange processes were also taken into account. Resulting energy and radial dependencies of ion fluxes and pitch-angle distributions for protons and various charge states of heavy ions are discussed.

A dynamic model is used to generalize the experimental data on galactic cosmic ray particle fluxes. The flux data are presented in the form of particle spectra beyond the solar modulation region.

An overview of the radiation belt and cosmic ray models currently available in Russia is presented. The models include trapped protons and electrons in the Earth's radiation belts, as well as solar and galactic cosmic rays. Aspects of possible refinement of these models are discussed.

Stacks of cellulose nitrate and cellulose triacetate plastic nuclear track detectors were exposed on a russian satellite in a low earth orbit during the solar particle events in October 1989. Extremely high fluences of solar particles with nuclear charges equal to or greater than 6 were registered. In CTA a charge identification for Z= 8–14 with a resolution of 0.5 charge units was achieved. Energy spectra and arrival directions of the detected particles were measured in both detector materials. The distribution of the arrival directions for ions in CTA shows a significant contribution of particles impinging from below the horizon.

Discrepancies between experimentally registered energetic electron fluxes and model predictions at low altitudes are stated. The main factors which could induce such changes in the trapped radiation environment are discussed. Preliminary results on the development of a more modern low-altitude trapped electron model, utilizing relatively recent data registered on ‘COSMOS-1986’ and ‘INTERCOSMOS-19’ satellites, are reported and discrepancies with AE-8 predicted fluxes at these altitudes are discussed.

A new method of numerical simulation of the proton pitch angle distribution (PAD) based on Liouville's theorem is presented. It yields good results for that region of the Earth's magnetosphere where the transport rate far exceeds the loss processes (charge exchange and Coulomb collisions) rate. Obtained numerical models of the proton PAD are in good agreement with the experimental data and explain all features of the PAD of proton fluxes with energy E > 50 keV experimentally measured in the Earth's magnetosphere at 3 R / R E R E is Earth's radius) and different MLT (magnetic local time) during geomagnetically quiet periods.

Experimental data about high-energy particle fluxes obtained in 1990–2000 in the Riabina-2 experiment on board MIR orbital station are analyzed in the sense of data failures. There are two types of failure. The first type is represented as sharp positive or negative spikes on the relatively smooth time profiles of the particle fluxes. The second type is randomly distributed data gaps with durations of up to tens minutes. These two kinds of the data failures are formalized in the form of “failure occurrence probability” (FOP). The comparison analysis of the FOP with solar activity, solar wind conditions and geomagnetic activity shows that one half of the observed data failures are owing to noise originating mostly from electronic equipment on board MIR station. The other half of the data failures are closely connected to geomagnetic storms and interplanetary disturbances. The space station surface charge and radio signal distortion in disturbed ionosphere are considered as possible phenomena responsible for the data failures.

Neutron measurement results obtained at SINP MSU since 1970 are presented. These measurements were made using techniques based on neutron moderation and subsequent detection in a Li6I(Eu) crystal or a He3 coronal counter. The measurements were mainly carried out in orbits with inclination of 52° and altitudes of 200– 450 km . The spatial and angular distributions of the measured neutron fluxes were studied. The albedo neutron flux was estimated according to the count rate difference for opposite detector orientations towards Earth and away from it. This flux is comparable to the local neutron flux outside the Brazil anomaly region, where local neutrons dominate. Neutron fluxes, generated by solar protons, were detected during a solar flare on June 6, 1991 for the first time. Their spectrum was estimated as a power law with α>2.

We report measurements of the energy spectra of anomalous cosmic ray N, O and Ne in the energy interval 5–25 MeV/nucleon made with stacks of cellulose nitrate sheets exposed on “Cosmos” satellites in Earth's vicinity in 1994. The successive etching was applied for the best charge identification.

A few exposures of CN-85 detectors on Earth-orbiting satellites in the period 1993–1994 show evidence for the reappearance of the radiation belt from geomagnetically trapped anomalous cosmic ray ions.