S.P. Ryumin

CORONAS-F satellite: Tasks for study of particle acceleration

Abstract A low altitude satellite with polar orbit, namely CORONAS-F has been launched on July 31, 2001. We briefly list the possibilities of a complex instrument SKL, and on the basis of similar measurements by CORONAS-I we illustrate the possible tasks for magnetospheric studies. Such orbit allows to sample with relatively high time resolution the projection series of various magnetospheric regions to low altitudes and to indicate changes within.

Measurements of neutron fluxes with energies from thermal to several MeV in near-Earth space: SINP results.

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 degrees 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 alpha>2.

Effects of the April 1994 Forbush events on the fluxes of the energetic charged particles measured on board CORONAS-I: their connection with conditions in the interplanetary medium

Abstract The SONG instrument on board CORONAS-I satellite (fluxes of protons E p >70 MeV and electrons E e >55 MeV ) observed the effects of the Forbush effects caused by interplanetary magnetic field sector boundary crossing and coronal mass ejection in April 1994. The latitudinal dependence of these effects is analyzed and compared with data from ground-based neutron monitors at different latitudes. It was found that while measurements by SONG instrument over the polar caps were in good agreement with the data of the neutron monitor at polar latitudes, at the middle latitudes during the Dst decreases, the cut-off rigidity variations were probably so strong that instead of the usual short-time decrease the SONG instrument detected a significant enhancement of particle fluxes. The influence of interplanetary medium conditions on the cosmic ray flux is analyzed and discussed.

Spatial distribution of low energy gamma-rays associated with trapped particles

According to the data from the SONG instrument on board the low altitude high inclination CORONAS-I satellite, the fluxes of gamma rays with energies between 120 keV and 8.3 MeV are reviewed. The observations were made during the interval from May 1994 to early July 1994. Comparison with energetic electron fluxes obtained from AE-8 model is done, and thus the gamma-ray production mechanism is discussed. Available data are used to investigate the fine spatial structure in the Brazilian anomaly, as well as to analyse outer zone of bremsstrahlung electrons. To do this, the L-B maps are constructed and energy spectral characteristics of gamma-ray fluxes are investigated.

A Wide-Range Neutron, X-Ray, and Gamma-Ray Spectrometer

A scintillation spectrometer based on a combination of CsI(Tl) and NaI(Tl) crystals was developed. The instrument ensures a reliable separation of X rays, γ rays, and neutrons by the difference in their signal shapes in an energy range of 0.03–30 MeV. The mean time of signal processing is 4 μs.

Latitude dependences of energetic neutrons and gamma-rays measured on the orbital complex SALYUT-7-COSMOS-1686

Abstract Neutron and gamma-ray measurements were made by the NEGA instrument in an experiment on board the orbital complex SALYUT-7-COSMOS-1686. This instrument, based on CsI(T1) scintillation crystal, allowed registration of gamma-rays in the energy range 1.5–65 MeV and neutrons with energies more than 20 MeV. Latitude variations in the fluxes and energy spectra for neutrons and gamma-rays are also obtained.

Energetic particle fluxes data base of “CORONAS-I” satellite observations

The data base DB SCR uses data obtained by the SCR instrument package on the CORONAS-I satellite. DB SCR contains information about fluxes of relativistic electrons (0.5-124 MeV), protons (1-300 MeV), nuclei (1-19 MeV/nucl) and gamma-radiation (0.1-7 MeV) in the low altitude region (500 km). The time resolution of the data is 2.5 s. Magnetic field parameters (B, magnetic latitude and longitude), L-shell and local times (LT and MLT) are included in DB SCR. Since all parameters are equivalents it is possible to perform the multidimensional analysis for any set of DB SCR parameters. The additional DB SCR software packages may be used to develop different semi-empirical models.